This specification describes the standard, required atomic XProc steps. A machine-readable description of these steps may be found in steps.xpl.
Many atomic steps are available for [XProc 3.0]. They are described in several specifications. This specification describes the general background common to all steps. A conformant processor must implement all of the steps in this specification. Additional steps may also be implemented.
The types given for options should be understood as follows:
- 
    Types in the XML Schema namespace, identified as QNames with the xs:prefix, as per the XML Schema specification with one exception. Anywhere anxs:QNameis specified, an EQName is allowed.
- 
    XPathExpression: As a string per [W3C XML Schema: Part 2], including whitespace normalization, and the further requirement to be a conformant Expression per [XPath 3.1].
- 
    XSLTSelectionPattern: As a string per [XSLT 3.0] conforming to an XSLT selection pattern.
- 
    XPathSequenceType: An XPath sequence type.
- 
    ContentType: A media type as defined in [RFC 2046].
- 
    ContentTypes: As a whitespace separated list of media types as defined in [RFC 2046].
Option values are often expressed using the shortcut syntax. In
these cases, the option shortcuts are generally treated as value
templates. However, for options of type map() or
array(), an expression is required
(there is no non-expression string which can ever be a legal value for
a map or array). Given that every value entered this way will have to
be a value template, and consequently every curly brace contained
within the expression will have to be escaped, values of type map or
array are defined to be expressions directly.
Some aspects of documents are generally unchanged by steps:
- 
When a step in this library produces an output document, the base URI of the output is the base URI of the step's primary input document unless the step's process explicitly sets an xml:baseattribute or the step's description explicitly states how the base URI is constructed.
- 
Steps are responsible for describing how document properties are transformed as documents flow through them. Many steps claim that the specified properties are preserved. Generally, it is the responsibility of the pipeline author to determine when this is inapropriate and take corrective action. However, it is the responsibility of the pipeline processor to assure that the content-typeproperty is correct. If a step transforms a document in a manner that is inconsistent with thecontent-typeproperty (accepting an XML document on the source port but producing a text document on the result, for example), the processor must assure that thecontent-typeproperty is appropriate. If a step changes thecontent-typein this way, it must also remove theserializationproperty
Also, in this specification, several steps use this element for result information:
<c:result>
    string
</c:result>
When a step uses an XPath to compute an option value, the XPath context is as defined in [XProc 3.0].
When a step specifies a particular version of a technology, implementations must implement that version or a subsequent version that is backwards compatible with that version. At user-option, they may implement other non-backwards compatible versions.
In this specification the words must, must not, should, should not, may and recommended are to be interpreted as described in [RFC 2119].
As described in PSVIs in XProc in XProc 3.0: An XML Pipeline Language,
steps may not produce PSVI output unless that behavior is explicitly
described. In this specification, the steps that may produce PSVI
output are the “identity” steps: p:identity,
p:store, and p:split-sequence (which must preserve 
PSVI properties that appear on their inputs). In addition, the
p:xslt and p:xquery steps may return documents with
PSVI annotations.
A conformant processor must support all of these steps.
The p:add-attribute step adds a single attribute to
a set of matching elements. The input document specified on the
  source is processed for matches specified by the 
    selection pattern in the match option. For each of these
matches, the attribute whose name is specified by the
attribute-name option is set to the attribute value
specified by the attribute-value option.
The resulting document is produced on the result
output port and consists of a exact copy of the input with the
exception of the matched elements. Each of the matched elements is
copied to the output with the addition of the specified attribute
with the specified value.
<p:declare-step type="p:add-attribute">
     <p:input port="source" content-types="xml html"/>
     <p:output port="result" content-types="xml html"/>
     <p:option name="match" as="xs:string" select="'/*'"/>         <!-- XSLTSelectionPattern -->
     <p:option name="attribute-name" required="true" as="xs:QName"/>
     <p:option name="attribute-value" required="true" as="xs:string"/></p:declare-step>
The value of the match option
must be an XSLTSelectionPattern. It
is a dynamic error (err:XC0023) if the selection pattern matches a node
which is not an element.
The value of the attribute-value option
must be a legal attribute value according to XML.
If an attribute with the same name as the expanded name
from the attribute-name option exists on the matched
element, the value specified in
the attribute-value option is used to set the
value of that existing attribute.  That is, the value of the
existing attribute is changed to the attribute-value
value. 
Note
If multiple attributes need to be set on the same
element(s), the p:set-attributes step can be used to set them
all at once.
This step cannot be used to add namespace declarations. It is a dynamic error (err:XC0059) if the QName
value in the attribute-name option uses the prefix
“xmlns”
or any other prefix that resolves to the namespace name
http://www.w3.org/2000/xmlns/.
 Note, however, that while namespace declarations cannot be
added explicitly by this step, adding an attribute whose name is in a
namespace for which there is no namespace declaration in scope on the
matched element may result in a namespace binding being added by
namespace fixup.
If an attribute named
xml:base is added or changed, the base URI
of the element must also be amended accordingly.
Document properties
All document properties are preserved.
The p:add-xml-base step exposes the base URI via
explicit xml:base attributes. The input document from the
source port is replicated to the result port
with xml:base attributes added to or corrected on each element as specified
by the options on this step.
<p:declare-step type="p:add-xml-base">
     <p:input port="source" content-types="xml html"/>
     <p:output port="result" content-types="xml html"/>
     <p:option name="all" as="xs:boolean" select="false()"/>       
     <p:option name="relative" as="xs:boolean" select="true()"/>   </p:declare-step>
The value of the all option
must be a boolean.
The value of the relative option
must be a boolean.
It is a dynamic error (err:XC0058)
if the all and relative options are
both true.
The p:add-xml-base step modifies its input as follows:
- 
For every element that is a child of the document node: force the element to have an xml:baseattribute with the document's [base URI] property's value as its value.
- 
For other elements: - 
If the alloption has the valuetrue, force the element to have anxml:baseattribute with the element's [base URI] value as its value.
- 
If the element's [base URI] is different from the its parent's [base URI], force the element to have an xml:baseattribute with the following value: if the value of therelativeoption istrue, a string which, when resolved against the parent's [base URI], will give the element's [base URI], otherwise the element's [base URI].
- 
Otherwise, if there is an xml:baseattribute present, remove it.
 
- 
Document properties
All document properties are preserved.
The p:archive step outputs on its result port an archive (usually
    binary) document, for instance a ZIP file. A specification of the contents of the archive may be
    specified in a manifest XML document on the manifest port. The step produces a
    report on the report port, which contains the manifest, amended with additional
    information about the archiving.
<p:declare-step type="p:archive">
     <p:input port="source" primary="true" content-types="any" sequence="true"/>
     <p:input port="manifest" content-types="xml" sequence="true">
          <p:empty/>
     </p:input>
     <p:input port="archive" content-types="any" sequence="true">
          <p:empty/>
     </p:input>
     <p:output port="result" primary="true" content-types="any" sequence="false"/>
     <p:output port="report" content-types="application/xml" sequence="false"/>
     <p:option name="format" as="xs:QName" select="'zip'"/>        
     <p:option name="relative-to" as="xs:anyURI?"/>                
     <p:option name="parameters" as="map(xs:QName, item()*)?"/>    </p:declare-step>
The p:archive step can perform several different operations on archives. The
    most common one will likely be creating an archive, but it could also, depending on the archive
    format, provide services like update, freshen or even merge. The only format implementations
      must support is [ZIP]. The list of formats
      supported by the p:archive step is
      implementation-defined.
The p:archive step has the following input ports:
- source
- 
        The (primary) sourceport is used to provide documents to be archived (for instance constructed by other steps). How and which of these documents are processed is governed by the document(s) appearing on the other input ports and the combination of options and parameters. See below for details. It is a dynamic error (err:XC0084) if two or more documents appear on thep:archivestep'ssourceport that have the same base URI or if any document that appears on thesourceport has no base URI.
- manifest
- 
        The manifestport can receive a manifest document that tells the step how to construct the archive. If no manifest document is provided on this port, a default manifest is constructed automatically. See Section 2.3.1, “The archive manifest”. It is a dynamic error (err:XC0100) if the document on portmanifestdoes not conform to the given schema.It is a dynamic error ( err:XC0112) if more than one document appears on the portmanifest.The default input for this port is the empty sequence. 
- archive
- 
        The archiveport is used to provide the step with existing archive(s) for operations like update, freshen or merge. Handling of ZIP files supports modifying archives appearing on thearchiveport (Section 2.3.2, “Handling of ZIP archives”). The list of archive formats that can be modified byp:archiveis implementation-defined. For instance an implementation that supports archive merging may accept more than one document on thearchiveport.The default input for this port is the empty sequence. 
The p:archive step has the following output ports:
- result
- 
        The (primary) resultport will output the resulting archive.
- report
- 
        The reportport will output a report about the archiving operation. This will be the same as the manifest (as provided on themanifestport or automatically created if there was no manifest provided), optionally amended with additional attributes and/or elements. The semantics of any additional attributes, elements and their values are implementation-defined.
The p:archive step has the following options:
- format
- 
        The format of the archive can be specified using the formatoption. Implementations must support the [ZIP] format, specified with the valuezip. It is implementation-defined what other formats are supported.
- parameters
- 
        The parametersoption can be used to supply parameters to control the archiving. The semantics of the keys and the allowed values for these keys are implementation-defined. It is a dynamic error (err:XC0079) if the mapparameterscontains an entry whose key is defined by the implementation and whose value is not valid for that key.
- relative-to
- 
        The relative-tooption is used in creating a manifest when no manifest is provided on themanifestport. If the option is relative, it is made absolute against the base URI of the element on which it is specified (p:with-optionor the step in case of a syntactic shortcut value). It is a dynamic error (err:XD0064) if the base URI is not both absolute and valid according to [RFC 3986].
The format of the archive is determined as follows:
- 
      If the formatoption is specified, this determines the format of the archive. Implementations must support the [ZIP] format, specified with the valuezip. It is implementation-defined what other formats are supported. It is a dynamic error (err:XC0081) if the format of the archive does not match the format as specified in theformatoption.
- 
      If no formatoption is specified or if its value is the empty sequence, the archive's format will be determined by the step, using thecontent-typedocument-property of the document on thearchiveport and/or by inspecting its contents. It is implementation-defined how the step determines the archive's format. Implementations should recognize archives in [ZIP] format.
It is a dynamic error (err:XC0085) if the format of the archive 
    does not match the specified format, cannot be understood, determined and/or processed.
An archive manifest specifies which documents will be considered in processing the archive. Every entry in the archive must have a corresponding entry in the manifest; if no such entry is provided, one will be constructed automatically (see below). If manifest entries are provided for documents that are not in the archive, how those are processed depends on the archive type and the parameters passed to the step.
A manifest is represented by a c:archive root element:
<c:archive>
    (c:entry* & 
     anyNonXProcElement*)
</c:archive>
The c:archive root element may contain additional
    implementation-defined attributes.
All entries in the archive must be present as c:entry child elements:
<c:entry
  name = string
  href = anyURI
  comment? = string
  method? = string
  level? = string
  content-type? = ContentType>
    anyElement*
</c:entry>
- 
        The nameattribute specifies the name of the entry in the archive.
- 
        The hrefattribute must be a valid URI according to [RFC 3986]. If its value is relative, it is made absolute against the base URI of the manifest. There are two possible cases:- 
        If the (absolute) hrefvalue is exactly the same as the base URI of a document appearing on thesourceport, that document is associated with this entry. If this entry is to be added to the archive, the associated document will be used. (Theserializationdocument property can be used to provide serialization properties.)
- 
        If no document on the sourceport has a base URI that is exactly the same as the (absolute)hrefvalue, the document at the specified URI is associated with this entry. These documents are stored in the archive “as is”; they must not be parsed and re-serialized.
 
- 
        
- 
        The methodattribute specifies how the entry should be compressed. The default compression method is implementation-defined. Implementations must support no compression, specified with the valuenone. It is implementation-defined what other compression methods are supported.
- 
        The levelattribute specifies the level of compression. The default compression method is implementation-defined. It is implementation-defined what compression levels are supported.
- 
        The content-typeattribute specifies the content-type of the entry as detected by the processor. It will be set byp:archive-manifestin constructing the manifest. It will be ignored byp:archive.
The p:archive step should strive to retain the order of
      the c:entry elements when constructing the archive. For instance, an e-book in EPUB
      format has a non-compressed entry that must be first in the archive. It should be possible to
      construct such an archive using p:archive.
The c:entry elements may contain additional
          implementation-defined attributes.
If no manifest entry is provided for a document appearing on the source port,
      the step will create a manifest entry for the document.
      (If no document arrives on the manifest port at all, a complete manifest
      document will be created.)
In a constructed manifest entry:
- 
    The entry’s hrefvalue is the base URI of the document.
- 
    The entry’s namevalue is derived from the base URI of the document and therelative-tooption.- 
    First, the value of the relative-tooption is made absolute. If the initial substring of the base URI is exactly the same as the resulting absolute value, then thenameis the portion of the base URI that follows that initial substring.
- 
    If there is no relative-tooption or if its value is not the initial substring of the base URI of the document, the name is the path portion of the URI (per [RFC 3986]). If the path portion begins with an initial slash, that slash is removed.
 
- 
    
      It is a dynamic error (err:XC0118) if an archive manifest is
        invalid according to the specification.
The format of the archive can be specified using the format option.
      Implementations must support the [ZIP] format,
      specified with the value zip. 
When ZIP archives are processed, every name in the
   manifest must be a relative path without a leading slash.
The parameters option can be used to supply parameters to control the
      archiving. For the zip format, the following parameters must
      be supported:
- command
- 
          Specifies what operation to perform. If not specified, its default value is update. Implementations must support the valuesupdate,create,freshen, anddelete. Thep:archivestep may support additional, implementation-defined commands for ZIP files. Unless otherwise specified, exactly zero or one ZIP archive can appear on thearchiveport for the commands described below. If no archive appears, a new archive will be created.- update
- 
                When the commandparameter is set toupdate, the ZIP archive will be updated:- 
                    For every entry in the ZIP file: - 
                        If the manifest contains a c:entrywith a matchingname, the entry in the ZIP file is updated with the document identified by thec:entryin the manifest.
- 
                        If the manifest does not contain a matching c:entry, the ZIP entry name is resolved against the base URI of the ZIP file.- 
                            If a document exists at that URI and either has no timestamp or has a timestamp more than the timestamp in the ZIP file, the entry in the ZIP file will be updated with the document at the resolved URI. 
- 
                            If no document exists at that URI, or the document cannot be accessed, or the document has a timestamp and the timestamp in the ZIP archive is more recent than the timestamp of the document, then the ZIP entry is unchanged. 
 
- 
                            
 
- 
                        
- 
                    For every c:entryin the manifest that does not have a matching entry in the ZIP file, the ZIP file will be updated by adding the document identified by thec:entryto the ZIP file.
 
- 
                    
- create
- 
                When the commandparameter is set tocreate, the ZIP archive will be created. Creating a ZIP archive behaves exactly likeupdateexcept that any timestamps are ignored; every ZIP entry will be updated or created if there is ac:entryor matching document for it. The document must be obtained by dereferencing the URI inhref. It is a dynamic error (err:XD0011) if the resource referenced by thehrefoption does not exist, cannot be accessed or is not a file.
- freshen
- 
                When the commandparameter is set tofreshen, existing files in the ZIP archive may be updated, but no new files will be added. Freshing a ZIP archive behaves exactly likeupdateexcept that only entries that already exist in the ZIP archive are considered.
- delete
- 
                When the commandparameter is set todelete, exactly one document in ZIP format must appear on thearchiveport. For every entry in the ZIP file:- 
                    If the manifest contains a c:entrywith a matchingname, the entry in the ZIP file is removed from the ZIP archive.
 If the manifest contains c:entryelements which do not have a matching entry in the ZIP archive, they are simply ignored.
- 
                    
 
- level
- 
          Specifies the default compression level for files added to or updated in the archive. If the levelattribute is specified on ac:entry, its value takes precedence for that entry. Values that must be supported for ZIP files are: “smallest”, “fastest”, “default”, “huffman”, and “none”.
- method
- 
          Specifies the default compression method for files added to or updated in the archive. If the methodattribute is specified on ac:entry, its value takes precedence for that entry. Values that must be supported for ZIP files are: “none” and “deflated”.
It is a dynamic error (err:XC0080) if the number of
        documents on the archive does not match the expected number of archive input
        documents for the given format and command.
Implementations of other archive formats should use the same parameter
      names if applicable. The value spaces for these parameters may be format-specific though.
        The actual parameter names supported by p:archive for a particular format
        are implementation-defined.
Document properties
No document properties are preserved.
The archive has no base-uri.
The p:archive-manifest creates an XML manifest file describing the contents of
    the archive appearing on its source port.
<p:declare-step type="p:archive-manifest">
     <p:input port="source" primary="true" content-types="any" sequence="false"/>
     <p:output port="result" primary="true" content-types="application/xml" sequence="false"/>
     <p:option name="format" as="xs:QName?"/>                      
     <p:option name="parameters" as="map(xs:QName, item()*)?"/>    
     <p:option name="relative-to" as="xs:anyURI?"/>                
     <p:option name="override-content-types" as="array(array(xs:string))?"/></p:declare-step>
The p:archive-manifest step inspects the archive appearing on its
      source port and outputs a manifest describing the contents of the archive on its
      result port. 
The format of the archive is determined as follows:
- 
      If the formatoption is specified, this determines the format of the archive. Implementations must support the [ZIP] format, specified with the valuezip. It is implementation-defined what other formats are supported.
- 
      If no formatoption is specified or if its value is the empty sequence, the archive's format will be determined by the step, using thecontent-typedocument-property of the document on thesourceport and/or by inspecting its contents. It is implementation-defined how the step determines the archive's format. Implementations should recognize archives in [ZIP] format.
It is a dynamic error (err:XC0085) if the format of the
      archive does not match the specified format, cannot be understood, determined and/or
      processed.
The parameters option can be used to supply parameters to control the
    archive manifest generation. The semantics of the keys and the allowed values for these
      keys are implementation-defined.
    It is a dynamic error (err:XC0079) if the map
        parameters contains an entry whose key is defined by the implementation and
      whose value is not valid for that key.
The relative-to option, when present, is used in creating the value of the
    manifest's c:entry/@href attribute. If the option is relative, it is made absolute
    against the base URI of the element on which it is specified (p:with-option or the
    step in case of a syntactic shortcut value). It is a dynamic
        error (err:XD0064) if the base URI is not both absolute and valid according to [RFC 3986].
The generated manifest has the format as described in Section 2.3.1, “The archive manifest”.
    Implementations must supply an c:entry element and its
      name and content-type attributes for every entry in the archive. The
    value of the generated manifest's c:entry/@href attribute will be determined in the
    same way as a base URI of an unarchived document by Section 2.38, “p:unarchive”. It is a dynamic error (err:XC0120) if the relative-to
      option is not present and the document on the source port does not have a base
      URI.
    Additional information provided for entries in p:archive-manifest is
        implementation-defined.
The override-content-types option can be used to partially override the
      content-type determination mechanism. If present, it must be an array of arrays, where the
      inner arrays consist of exactly two strings: 
- 
        The first member in an inner array must be a regular expression as specified in [XPath and XQuery Functions and Operators 3.1], section 7.61 “ Regular Expression Syntax”. It is a dynamic error (err:XC0147) if the specified value is not a valid XPath regular expression.
- 
        The second member in an inner array must be a valid a MIME content-type. It is a dynamic error ( err:XD0079) if a supplied content-type is not a valid media type of the form “type/subtype+exttype/subtype
It is a dynamic error (err:XC0146) if the specified value
        for the override-content-types option is not an array of arrays, where the
        inner arrays have exactly two members of type xs:string.
Determining an archive entry's content-type is as follows:
- 
        The XPath regular expressions (the first members of the inner arrays) will be matched against the path of the entry in the archive. This will be done in the order of appearance in the outer array (so order is significant). The matching is done unanchored: it is a match if the regular expression matches part of the entry's path. Informally: matching behaves like applying the XPath matches#2function, like inmatches($path-in-archive, $regular-expression).NoteDepending on how archives are constructed, the path of an entry in an archive can be with or without a leading slash. Usually it will be without. For archives constructed by p:archiveno leading slash will be present.
- 
        If a match is found, the content-type (the second member of the inner array for which the match was found) is used as the entry's content-type. 
- 
        If no match was found for all inner arrays, the normal (implementation-defined) mechanism for determining the content-type is used. 
For example: setting the override-content-types option to [
        ['.rels$', 'application/xml'], ['^special/', 'application/octet-stream'] ] means that
      all files ending with .rels will get the content-type
        application/xml. All files in the archive's special directory
      (including sub-directories) will get the content-type
      application/octet-stream.
Document properties
No document properties are preserved. The
      manifest has no base-uri.
The p:cast-content-type step creates a new document by 
      changing the media type of its input. If the value of the content-type
   option and the current media type of the document on source port are
   the same, this document will appear unchanged on result port.
<p:declare-step type="p:cast-content-type">
     <p:input port="source" content-types="any"/>
     <p:output port="result" content-types="any"/>
     <p:option name="content-type" required="true" as="xs:string"/>
     <p:option name="parameters" as="map(xs:QName,item()*)?"/>     </p:declare-step>
The input document is transformed from one media type to another.
      It is a dynamic error (err:XD0079) if a supplied content-type is not 
         a valid media type of the form 
         “type/subtype+exttype/subtypeerr:XC0071) if the p:cast-content-type step
         cannot perform the requested cast.
   
The parameters can be used to supply parameters to
      control casting. The semantics of the keys and the allowed values for
         these keys are implementation-defined.
      It is a dynamic error (err:XC0079) if the map
         parameters contains an entry whose key is defined by the
         implementation and whose value is not valid for that key.
- 
            Casting from one XML media type to another simply changes the “ content-type” document property.
- 
            Casting from an XML media type to an HTML media type changes the “ content-type” document property and removes any serialization property.
- 
            Casting from an XML media type to a JSON media type converts the XML into JSON. The precise nature of the conversion from XML to JSON is implementation-defined. If the input document is an XML representation of JSON as defined in [XPath and XQuery Functions and Operators 3.1], implementations must produce the same result as fn:parse-json(fn:xml-to-json())by default. If the input document has ac:param-setdocument element, an instance ofmap(xs:QName, xs:string)must be returned that represents the document'sc:paramelements. The serialization property is removed.
- 
            Casting from an XML media type to a text media type serializes the XML document by calling fn:serialize($doc, $param)where$docis the document on thesourceport and$paramis the serialization property of this document. The resulting string is wrapped by a document node and returned on theresultport. The serialization property is removed.
- 
            Casting from an XML media type to any other media type must support the case where the input document is a c:datadocument. The resulting document will have the specified media type and a representation that is the content of thec:dataelement after decoding the base64 encoded content The serialization property is removed.It is a dynamic error ( err:XC0072) if thec:datacontains content is not a valid base64 string.It is a dynamic error ( err:XC0073) if thec:dataelement does not have acontent-typeattribute.It is a dynamic error ( err:XC0074) if thecontent-typeis supplied and is not the same as thecontent-typespecified on thec:dataelement.Casting from an XML media type to any other media type when the input document is not a c:datadocument is implementation-defined.
- 
            Casting from an HTML media type to an XML media type changes “ content-type” document property and removes any serialization property.
- 
            Casting from an HTML media type to another HTML media type changes “ content-type” document property.
- 
            Casting from an HTML media type to a JSON media type is implementation-defined. 
- 
            Casting an an HTML media type to a text media type serializes the HTML document by calling fn:serialize($doc, $param)where$docis the document on thesourceport and$paramis the serialization property of this document. The resulting string is wrapped by a document node and returned on theresultport. The serialization property is removed.
- 
            Casting from an HTML media type to any other media type is implementation-defined. 
- 
            Casting from a JSON media type to an XML media type converts the JSON into XML. An implementation must support the format specified in section “XML Representation of JSON” of [XPath and XQuery Functions and Operators 3.1] as default for the resulting XML. It is implementation-defined whether other result formats are supported. The serialization property is removed. 
- 
            Casting from a JSON media type to an HTML media type is implementation-defined. 
- 
            Casting from a JSON media type to another JSON media type changes “ content-type” document property.
- 
            Casting from a JSON media type to a text media type serializes the JSON document by calling fn:serialize($doc, $param)where$docis the document on thesourceport and$paramis the serialization property of this document. The resulting string is wrapped by a document node and returned on theresultport. The serialization property is removed.
- 
            Casting from a JSON media type to any other media type is implementation-defined. 
- 
            Casting from a text media type to an XML media type parses the text value of the document on sourceport by callingfn:parse-xml. It is a dynamic error (err:XD0049) if the text value is not a well-formed XML document. The serialization property is removed.
- 
            Casting from a text media type to an HTML media type parses the text value of the document on sourceport into an XPath data model document that contains a tree of elements, attributes, and other nodes. The precise way in which text documents are parsed into the XPath data model is implementation-defined. It is a dynamic error (err:XD0060) if the text document can not be converted into the XPath data model. The serialization property is removed.
- 
            Casting from a text media type to a JSON media type parses the text value of the document on sourceport by callingfn:parse-json($doc, $par)where$docis the text document and$paris theparameteroption. It is a dynamic error (err:XD0057) if the text document does not conform to the JSON grammar, unless the parameter liberal is true and the processor chooses to accept the deviation. It is a dynamic error (err:XD0058) if the parameter duplicates is reject and the text document contains a JSON object with duplicate keys. It is a dynamic error (err:XD0059) if the parameter map contains an entry whose key is defined in the specification offn:parse-jsonand whose value is not valid for that key, or if it contains an entry with the key fallback when the parameterescapewithtrue()is also present. The serialization property is removed.
- 
            Casting from a text media type to another text media type changes “ content-type” document property.
- 
            Casting from a text media type to any other media type is implementation-defined. 
- 
            Casting from a non-XML media type to an XML media type produces an XML document with a c:datadocument element. The original media type will be preserved in thecontent-typeattribute on thec:dataelement.<c:data
 content-type = ContentType
 charset? = string
 encoding? = string>
 string
 </c:data>The content of the c:dataelement is the base64 encoded representation of the non-XML content. The serialization property is removed.
- 
            Casting from any other media type to a HTML media type, a JSON media type or a text document is implementation-defined. 
- 
            Casting from any other media type to any other media type is implementation-defined. 
Document properties
All document
         properties are preserved except the content-type property
         which is updated accordingly and the serialization property
         which is removed by some casting methods.
The p:compare step compares two documents for
equality.
<p:declare-step type="p:compare">
     <p:input port="source" primary="true" content-types="any"/>
     <p:input port="alternate" content-types="any"/>
     <p:output port="result" content-types="application/xml"/>
     <p:output port="differences" content-types="any" sequence="true"/>
     <p:option name="parameters" as="map(xs:QName,item()*)?"/>     
     <p:option name="method" as="xs:QName?"/>                      
     <p:option name="fail-if-not-equal" as="xs:boolean" select="false()"/></p:declare-step>
This step takes single documents on each of two ports and
compares them. If method is not specified, or if
deep-equal is specified, the comparison
uses fn:deep-equal
(as defined in [XPath and XQuery Functions and Operators 3.1]). Implementations of p:compare
must support the deep-equal method;
other supported methods are implementation-defined.
It is a dynamic error (err:XC0076) if
the comparison method specified in p:compare
is not supported by the implementation.
It is a dynamic error (err:XC0077) if
the media types of the documents supplied are incompatible with the
comparison method.
It is a dynamic error (err:XC0019)
if the documents are not equal according to the specified comparison
method, and the value of the
fail-if-not-equal option is
true. If the documents are equal, or if the
value of the fail-if-not-equal option is
false, a c:result document is produced
with contents true if the documents are equal,
otherwise false.
If
fail-if-not-equal is false, and the
documents differ, an implementation-defined
summary of the differences between the two documents may appear on the
differences port.
Document properties
No document properties are preserved.
The comparison document has no base-uri.
The p:compress step serializes the document appearing on its source
    port and outputs a compressed version of this on its result port.
<p:declare-step type="p:compress">
     <p:input port="source" primary="true" content-types="any" sequence="false"/>
     <p:output port="result" primary="true" content-types="any" sequence="false"/>
     <p:option name="format" as="xs:QName" select="'gzip'"/>       
     <p:option name="serialization" as="map(xs:QName,item()*)?"/>  
     <p:option name="parameters" as="map(xs:QName, item()*)?"/>    </p:declare-step>
The p:compress step first serializes the document appearing on its
      source. It then compresses the outcome of this serialization and outputs the
    result on its result port.
The p:compress step has the following options:
- format
- 
        The format of the compression can be specified using the formatoption. Implementations must support the [GZIP] format, specified with the valuegzip. It is implementation-defined what other formats are supported. It is a dynamic error (err:XC0202) if the compression format cannot be understood, determined and/or processed.
- parameters
- 
        The parametersoption can be used to supply parameters to control the compression. The semantics of the keys and the allowed values for these keys are implementation-defined. It is a dynamic error (err:XC0079) if the mapparameterscontains an entry whose key is defined by the implementation and whose value is not valid for that key.
- serialization
- 
        The serializationoption is provided to control the serialization of content before compression takes place. If the document to be stored has aserializationproperty, the serialization is controlled by the merger of the two maps where the entries in theserializationproperty take precedence. Serialization is described in [XProc 3.0].
Document properties
All document properties are preserved, except for the
        content-type property which is updated accordingly and the
        serialization property which is removed.
The p:count step counts the number of documents in
the source input sequence and returns a single document
on result containing that number. The generated document
contains a single c:result element whose contents is the
string representation of the number of documents in the
sequence.
<p:declare-step type="p:count">
     <p:input port="source" content-types="any" sequence="true"/>
     <p:output port="result" content-types="application/xml"/>
     <p:option name="limit" as="xs:integer" select="0"/>           </p:declare-step>
If the limit option is specified
and is greater than zero, the p:count step will count at most
that many documents. This provides a convenient mechanism to discover,
for example, if a sequence consists of more than 1 document, without
requiring every single document to be buffered before processing can
continue.
Document properties
No document properties are preserved.
The count document has no base-uri.
The p:delete step deletes items specified by a selection pattern from the
source input document and produces the resulting document,
with the deleted items removed, on the result port.
<p:declare-step type="p:delete">
     <p:input port="source" content-types="xml html"/>
     <p:output port="result" content-types="text xml html"/>
     <p:option name="match" required="true" as="xs:string"/>       <!-- XSLTSelectionPattern --></p:declare-step>
The value of the match option must be an
XSLTSelectionPattern. A selection pattern may match multiple items to be
deleted.
If an element is selected by the match option, the
entire subtree rooted at that element is deleted.
It is a dynamic error (err:XC0023) if the
match option matches the document node.
This step cannot be used to remove namespaces. It is a dynamic error (err:XC0062) if the
match option matches a namespace node.
Also, note that deleting an attribute named
xml:base does not change the base URI
of the element on which it occurred.
Document properties
If the resulting document contains exactly one text node,
      the content-type property is changed to text/plain and the 
      serialization property is removed, while all other document properties are 
      preserved. For other document types, all document properties are preserved.
The p:error step generates a dynamic error using the input provided
to the step.
<p:declare-step type="p:error">
     <p:input port="source" sequence="true" content-types="text xml"/>
     <p:output port="result" sequence="true" content-types="any"/>
     <p:option name="code" required="true" as="xs:QName"/>         </p:declare-step>
This step uses the document provided on its input as the content
of the error raised. An instance of the
c:errors element will be produced on the error output port, as is
always the case for dynamic errors.
The error generated can be caught by a p:try just like any
other dynamic error.
For authoring convenience, the p:error step is
declared with a single, primary output port. With respect to connections,
this port behaves like
any other output port even though nothing can ever
appear on it since the step always fails.
For example, given the following invocation:
<p:error xmlns:my="http://www.example.org/error"
         name="bad-document" code="my:unk12">
   <p:with-input port="source">
     <message>The document element is unknown.</message>
   </p:with-input>
</p:error>The error vocabulary element (and document) generated on the error output port would be:
<c:errors xmlns:c="http://www.w3.org/ns/xproc-step"
          xmlns:p="http://www.w3.org/ns/xproc"
          xmlns:my="http://www.example.org/error">
 <c:error name="bad-document" type="p:error"
          code="my:unk12"><message>The document element is unknown.</message>
</c:error>
</c:errors>The href,
line and column,
or offset, might also be present on the
c:error to identify the location of the p:error
element in the pipeline.
Document properties
No document properties are preserved but that’s irrelevant as no document is ever produced.
The p:filter step selects portions of the source document
based on a (possibly dynamically constructed) XPath select expression.
<p:declare-step type="p:filter">
     <p:input port="source" content-types="xml html"/>
     <p:output port="result" sequence="true" content-types="text xml html"/>
     <p:option name="select" required="true" as="xs:string"/>      <!-- XPathExpression --></p:declare-step>
This step behaves just like an p:input with
a select expression except that the select
expression is computed dynamically.
Document properties
No document properties are preserved.
The base-uri property of each document will reflect the
base URI of the selected node(s).
The p:hash step generates a hash, or digital “fingerprint”,
for some value and injects it into the source document.
<p:declare-step type="p:hash">
     <p:input port="source" primary="true" content-types="xml html"/>
     <p:output port="result" content-types="text xml html"/>
     <p:option name="parameters" as="map(xs:QName,item()*)?"/>     
     <p:option name="value" required="true" as="xs:string"/>       
     <p:option name="algorithm" required="true" as="xs:QName"/>    
     <p:option name="match" as="xs:string" select="'/*/node()'"/>  <!-- XSLTSelectionPattern -->
     <p:option name="version" as="xs:string?"/>                    </p:declare-step>
The value of the algorithm option must be a QName.
If it does not have a prefix, then it must be one of the following values:
“crc”, “md”, or “sha”.
If a version is not specified, the
default version is algorithm-defined. For “crc” it
is 32, for “md” it is 5, for “sha”
it is 1.
A hash is constructed from the string specified in the
value option using the specified algorithm and version.
Implementations must support
[CRC32],
[RFC 1321], and [SHA1]
hashes. It is
implementation-defined what other algorithms are
supported.
The resulting hash should be returned as a string of
hexadecimal characters.
The value of the match option must be an
XSLTSelectionPattern.
The hash of the specified value is computed using the algorithm and
parameters specified. It is a
dynamic error (err:XC0036) if the requested hash algorithm is not
one that the processor understands or if the value or parameters are
not appropriate for that algorithm.
The matched nodes are specified with the selection pattern in the
match option. For each matching node, the string
value of the computed hash is used in the output (if more than one node
matches, the same hash value is used in each match).
Nodes that do not
match are copied without change.
If the expression given in the match option
matches an attribute, the hash is used as the new
value of the attribute in the output.
If the attribute is named “xml:base”, the base URI
of the element must also be amended accordingly.
If the document node is matched, the entire document is replaced by a text node
with the hash. What appears on port result is a text document with the
text node wrapped in a document node.
If the expression matches any other kind of node, the entire node (and not just its contents) is replaced by the hash.
Document properties
If the resulting document contains exactly one text node,
      the content-type property is changed to text/plain and the 
      serialization property is removed, while all other document properties are 
      preserved. For other document types, all document properties are preserved.
The p:http-request step allows authors to interact
with resources over HTTP or related protocols. Implementations
must support the http and
https protocols.
(Implementors are encouraged to support as many protocols as
practical. In particular, pipeline authors may attempt to use
p:http-request to load documents with computed URIs using
the file: scheme.)
<p:declare-step type="p:http-request">
     <p:input port="source" content-types="any" sequence="true"/>
     <p:output port="result" primary="true" content-types="any" sequence="true"/>
     <p:output port="report" content-types="application/json"/>
     <p:option name="href" as="xs:anyURI" required="true"/>        
     <p:option name="method" as="xs:string?" select="'GET'"/>      
     <p:option name="serialization" as="map(xs:QName,item()*)?"/>  
     <p:option name="headers" as="map(xs:string, xs:string)?"/>    
     <p:option name="auth" as="map(xs:string, item()+)?"/>         
     <p:option name="parameters" as="map(xs:QName, item()*)?"/>    
     <p:option name="assert" as="xs:string" select="'.?status-code lt 400'"/></p:declare-step>
The p:http-request step performs the HTTP request
specified by the method option against the URI specified in
the href option. In simple cases, for example, a GET
request on an unauthenticated URI, nothing else is necessary to form a
complete request.
If the method, for example, POST, supports a body, the request
body is constructed using the document(s) appearing on the
source port. For the convenience of pipeline authors,
documents may appear on the source port even when the
request method (such as GET or HEAD) does not define the semantics of
a payload. If the semantics are undefined, the documents are
ignored when constructing the request unless the
parameters option specifies
“send-body-anyway” as true().
The headers for the request come from the
headers option (see below). If exactly one document
appears on the source port, its document properties also
contribute to the overall request headers.
The response from the HTTP request appears on the
result and report ports. Any documents
contained in the response body will appear on the result
port. Each document in the response will be parsed according to
its content-type (but see “override-content-type”
in the parameters option).
Details about the outcome of the request will appear as a map on
the report port. The map will always contain
“status-code” (an xs:integer) and
“headers” (a map(xs:string,
xs:string)). The header map may be empty. Header names are
converted to lowercase.
The p:http-request step has the following options:
- href
- 
  The hrefoption specifies the request’s IRI. Relative values are resolved against the base URI of the element on which the option is specified (the relevantp:with-optionor the step element in the case of a syntactic shortcut value).Fragment identifiers are removed before making the request. Query parameters are passed through unchanged. It is a dynamic error ( err:XC0128) if the URI’s scheme is unknown or not supported. It is the pipeline author’s responsibility to escape problematic UTF-8 characters in thehrefvalue, for example withescape-html-uri().
- method
- 
  The methodspecifies the HTTP request method. The value is implicitly turned into an uppercase string if necessary. It is implementation defined which HTTP methods are supported. An implementation should implement at least the methodsGET,POST,PUT,DELETE, andHEAD(for HTTP and HTTPS). It is a dynamic error (err:XC0122) if the given method is not supported.
- serialization
- 
  The serializationoption is used to control the serialization of documents for the request body. If a document has a “serialization” document property, the effective value of the serialization options is the union of the two maps, where the entries in the “serialization” document property take precedence.
- headers
- 
  The key/value pairs in the headersmap are used to construct the request headers. Each map key is used as a header name and the value associated with that key in the map is used as the header value.If a single document appears on the sourceport, then document properties on that document may be added as additional headers. For XML, HTML, and text documents with aserializationdocument property having anencodingkey, acharsetis appended to the createdcontent-typeheader of the HTTP request. Properties in thehttp://www.w3.org/ns/xproc-httpnamespace will be added to the headers, using the local-name of the property QName as the header name. These properties are only copied if they are not specified in theheadermap. In other words, if the same header name appears in both places, the value from the map is used and the value from the document properties is ignored. (Header names are case-insensitive, so a case-insensitive comparison must be performed.) If multiple documents appear on thesourceport, none of their properties are used in the request headers.The behavior of the p:http-requestdepends on the headers specified. In particular:- content-type
- 
      If a content-typeheader is provided, it will be used. For a single document request, this overrides the content type value of the document. If the content type specified begins with “multipart/”, a multipart request will be sent to the server.It is a dynamic error ( err:XD0079) if a supplied content-type is not a valid media type of the form “type/subtype+exttype/subtype
- transfer-encoding
- 
      If a transfer-encodingheader is provided, the request must be sent with that encoding. It is a dynamic error (err:XC0131) if the processor cannot support the requested encoding.
- authorization
- 
      The authorizationheader is used to authenticate a request. If theauthoption is specified, any key or property that would have contributed a header named “authorization” (irrespective of case) is ignored. The authorization header is determined exclusively by theauthoption when it is present.
 HTTP headers are case-insensitive but keys in maps are not; be careful when specifying the request headers. It is a dynamic error ( err:XC0127) if theheadersmap contains two keys that are the same when compared in a case-insensitive manner. (That is, whenfn:uppercase($key1) = fn:uppercase($key2).)
- auth
- 
  Many web services are only available to authenticated users, that is, to users who have “logged in”. The authoption allows the pipeline author to specify information that may be required to generate an “Authorization” header. The standard values support HTTP “Basic” and “Digest” authentication, but other authentication methods are allowed.The following standard keys are defined: - username(- xs:string)
- 
  The username. 
- password(- xs:string)
- 
  The password associated with the username. 
- auth-method(- xs:string)
- 
  The authentication method. Appropriate values for the “ auth-method” key are “Basic” or “Digest” but other values are allowed. If the authentication method is “Basic” or “Digest”, authentication is handled as per [RFC 2617]. The interpretation of values associated with the “auth-method” key other than “Basic” or “Digest” is implementation defined.
- send-authorization(- xs:boolean)
- 
  The “ send-authorization” key can be used to attempt to allow the request to avoid an authentication challenge. If the “send-authorization” key is “true()”, and the authentication method specified by the value associated with the “auth-method” key supports generation of an “Authorization” header without a challenge, then the header is generated and sent on the first request. If the “send-authorization” key is absent or does not have the value “true”, the first request is sent without an “Authorization” header.
 Other key value pairs in map “ auth” are implementation defined. It is a dynamic error (err:XC0123) if any key in the “auth” map is associated with a value that is not an instance of the required type.If the initial response to the request is an authentication challenge, the values provided in the authmap and any relevant data from the challenge are used to generate an “Authorization” header and the request is sent again. If that authorization fails, the request is not retried.It is a dynamic error ( err:XC0003) if a “username” or a “password” key is present without specifying a value for the “auth-method” key, if the requestedauth-methodisn't supported, or the authentication challenge contains an authentication method that isn't supported. All implementations must support “Basic” and “Digest” authentication per [RFC 2617].
- parameters
- 
    The parameteroption can be used to provide values for fine tuning the construction of the request and/or handling of the server response. A number of parameters are defined in this specification. It is implementation defined which other key/value pairs in theparametersoption are supported.- override-content-type (xs:string)
- 
      Ordinarily, the value of the content-typeheader provided in the server response controls the interpretation of any body in the response. If the “override-content-type” parameter is provided, then its value is used to interpret the body. The content-type header that appears on thereportport is not changed. It is a dynamic error (err:XD0079) if a supplied content-type is not a valid media type of the form “type/subtype+exttype/subtypeerr:XC0030) if the response body cannot be interpreted as requested (e.g.application/jsonto overrideapplication/xmlcontent).
- http-version (xs:string)
- 
        The http-versionparameter indicates which version of HTTP must be used for the request. It is a dynamic error (err:XC0129) if the requested HTTP version is not supported.
- accept-multipart (xs:boolean)
- 
        If the accept-multipartparameter is present and explicitly has the valuefalse(), a dynamic error will be raised, if a multipart response is received from the server. This feature is a convenience for pipeline authors as it will raise an error when the multipart request is received, rather than having the presence of a sequence raise an error further along in the pipeline, or simply producing anomalous results. It is a dynamic error (err:XC0125) if the key “accept-multipart” as the valuefalse()and a multipart response is detected.
- override-content-encoding (xs:string)
- 
          If the “ override-content-encoding” parameter is present, the response will be treated as if the response contained a “content-encoding” header with the specified value. The content-encoding header that appears on thereportport is not changed. It is a dynamic error (err:XC0132) if the override content encoding cannot be supported.
- permit-expired-ssl-certificate (xs:boolean)
- 
          If “ permit-expired-ssl-certificate” is true, then the processor should not reject responses where the server provides an expired SSL certificate.
- permit-untrusted-ssl-certificate (xs:boolean)
- 
          If “ permit-untrusted-ssl-certificate” is true, then the processor should not reject response where the server provides an SSL certificate which is not trusted, for example, because the certificate authority (CA) is unknown.
- follow-redirect (xs:integer)
- 
          The “ follow-redirect” parameter allows the pipeline author to specify the step’s behaviour in the case of a redirect response. A value of0indicates that redirects are not to be followed,-1indicates that redirects are to be followed indefinitely, and a specific number indicates the maximum number of redirects to follow. The default behaviour in case of a redirect response is implementation defined.
- timeout (xs:integer)
- 
          If a “ timeout” is specified, it must be a non-negative integer. It controls the time the XProc processor waits for the request to be answered. If a value is given, it is taken as the number of seconds to wait for the response to be delivered. If no response is received after that time, the request is terminated and a status-code408is assumed.
- fail-on-timeout (xs:boolean)
- 
          If “ fail-on-timeout” is true, a dynamic error is raised if a408response is received (either as a consequence of setting a value for the “timeout” parameter or as status code returned by a server). It is a dynamic error (err:XC0078) if the value associated with the “fail-on-timeout” is associated withtrue()and a HTTP status code408is encountered. If “fail-on-timeout” is true, it prevents any dynamic error with codeC0126resulting from theassertoption to be raised for request's timeout.NotePlease note that the “ fail-on-timeout” parameter is different from the “timeout” option on thep:http-requeststep (see Controlling long running steps in XProc 3.0: An XML Pipeline Language). If the step does not finish in the specified time,D0053is raised. If the request does not finish in time, andfail-on-timeoutis true,C0078is raised. The actual times after which a timeout is detected may also differ slightly.
- status-only (xs:boolean)
- 
          If the “ status-only” parameter is true, this indicates that the pipeline author is only interested in the response code. An empty sequence is always returned on theresultport in this case. The implementation may save resources by ignoring the response body. The map on thereportwill contain the status code and an empty map for “headers”.
- suppress-cookies (xs:boolean)
- 
          If the “ suppress-cookies” parameter is true, the implementation must not send any cookies with the request.
- send-body-anyway (xs:boolean)
- 
          If the “ send-body-anyway” parameter is true, and one or more documents appear on thesourceport, a request body is constructed from the documents and sent with the request, even if the semantics of sending a body are not specified for the HTTP method in use.
 It is a dynamic error ( err:XC0124) if any key in the “parameters” map is associated with a value that is not an instance of the required type.
- override-content-type (
- assert (xs:string)
- 
        The assertoption can be used by pipeline authors to raise a dynamic error if the response does not fulfill the expectations of the receiver. The option's value (if present) is interpreted as an XPath expression which will be executed using the map that appears on thereportport as its context item. If the effective boolean value of the expression isfalse(), a dynamic error is raised. It is a dynamic error (err:XC0126) if the XPath expression inassertevaluates tofalse. Implementations should provide an XML representation of the map used as the context item with the error document to enable pipelines to access the error's cause.
If more than one document appears on the source
port, or if the specified “content-type” header
begins “multipart/”, a multipart request will be
constructed, per [RFC 1521]. The content type of
the request is derived from the “content-type”
header:
- 
If the “ content-type” header specifies a multipart content type, that value will be used as the content type. If the header includes aboundaryparameter, that value will be used as the boundary.
- 
If the “ content-type” header is not specified, “multipart/mixed” will be used.
- 
It is a dynamic error ( err:XC0133) if more than one document appears on thesourceport and acontent-typeheader is present and the content type specified is not a multipart content type.
A multipart request must have a boundary marker, if one isn’t specified in the content type, the implementation must construct one. It is implementation-defined how a multipart boundary is constructed. Implementations are not required to guarantee that the constructed value does not appear accidentally in the multipart data. If it does, the request will be malformed; pipeline authors must provide a boundary if they wish to assure that this cannot happen.
Each document in the sequence is serialized. If the document has
a “serialization” document property, its values
are used to determine how serialization is performed.
All of the document properties in the
http://www.w3.org/ns/xproc-http namespace will be added
as headers for the part, using the local-name of the property QName as
the header name. In particular, this is how the
“id”, “description”,
“disposition” and other multipart headers can be
provided.
When a multipart response is received, each part is interpreted according to it’s content type and a pipeline document is constructed. Any additional headers associated with the part are added to the document properties of the constructed document.
The multipart response is the resulting sequence of documents.
Document properties
No document properties are preserved.
The p:identity step makes a verbatim copy of its input
available on its output.
<p:declare-step type="p:identity">
     <p:input port="source" sequence="true" content-types="any"/>
     <p:output port="result" sequence="true" content-types="any"/></p:declare-step>
If the implementation supports passing PSVI annotations between
steps, the p:identity step must preserve
any annotations that appear in the input.
Document properties
All document properties are preserved.
The p:insert step inserts the
insertion port's document into the source
port's document relative to the matching elements in the
source port's document.
<p:declare-step type="p:insert">
     <p:input port="source" primary="true" content-types="xml html"/>
     <p:input port="insertion" sequence="true" content-types="xml html"/>
     <p:output port="result" content-types="xml html"/>
     <p:option name="match" as="xs:string" select="'/*'"/>         <!-- XSLTSelectionPattern -->
     <p:option name="position" as="xs:token" values="('first-child','last-child','before','after')" select="'after'"/></p:declare-step>
The value of the match option
must be an XSLTSelectionPattern. It
is a dynamic error (err:XC0023) if that pattern matches
an attribute or a namespace node.
Multiple matches are
allowed, in which case multiple copies of the insertion
documents will occur. If no elements match, then the document is
unchanged.
The value of the position option must be an NMTOKEN in
the following list:
- 
“ first-child” - the insertion is made as the first child of the match;
- 
“ last-child” - the insertion is made as the last child of the match;
- 
“ before” - the insertion is made as the immediate preceding sibling of the match;
- 
“ after” - the insertion is made as the immediate following sibling of the match.
It is a dynamic error (err:XC0025)
if the selection pattern matches anything other than an element or a document
node and the value of the position option is
“first-child” or
“last-child”. It is a
dynamic error (err:XC0024) if the selection pattern matches a document
node and the value of the position is “before” or
“after”.
As the inserted elements are part of the output of the step they
are not considered in determining matching elements. If an empty sequence
appears on the insertion port, the result will be the same
as the source.
Document properties
All document properties on the
source port are preserved. The document properties on the
insertion port are not preserved or present in the result document.
The p:json-join step joins the sequence of documents on port source
into a single JSON document (an array) appearing on port result. If the sequence on
port source is empty, the empty sequence is returned on
port result.
<p:declare-step type="p:json-join">
     <p:input port="source" sequence="true" content-types="any"/>
     <p:output port="result" content-types="application/json"/>
     <p:option name="flatten-to-depth" as="xs:string?" select="'0'"/></p:declare-step>
The step inspects the documents on port source in turn to create the
  resulting array:
- 
    If the document under inspection is a JSON document representing an array, the array is copied to the resulting array according to the setting of option flatten-to-depth.
- 
    For every other type of JSON document, for XML documents, HTML documents, or text documents, their XDM representation is appended to the resulting array. 
- 
    It is implementation defined if p:json-joinis able to process document types not mentioned yet, i.e. types of binary documents. If a processor supports a given type of documents, an entry is created as described above. It is a dynamic error (err:XC0111) if a document of an unsupported document type appears on portsourceofp:json-join.
The option flatten-to-depth controls whether and to which
depth members of an array appearing on port source are flattened.
It is a dynamic error (err:XC0119) if flatten is
neither “unbounded”, nor a string that may be cast to a non-negative integer.
An integer value of 0, which is the default, means that no 
flattening takes place, so the array appearing on port source will
be contained as an array in the resulting array. An integer value of 1
means that an array on port source is flattened, i.e. the members
of that array will appear as individual members in the resulting array. Any value greater
than 1 means that the flattening is applied recursively to arrays in
arrays up to the given depth. A value of “unbounded” means that all
arrays in arrays will be flattened. As a consequence, the resulting array appearing on
port result will not have any arrays as members. 
Document properties
No document properties are preserved.
The joined document has no base-uri.
The p:json-merge step merges the sequence of appearing
on port source into a single JSON object appearing on port
result. If the sequence on
port source is empty, the empty sequence is returned on
port result.
<p:declare-step type="p:json-merge">
     <p:input port="source" sequence="true" content-types="any"/>
     <p:output port="result" content-types="application/json"/>
     <p:option name="duplicates" as="xs:token" values="('reject', 'use-first', 'use-last', 'use-any', 'combine')" select="'use-first'"/>
     <p:option name="key" as="xs:string" select="'concat("_",$p:index)'"/><!-- XPathExpression --></p:declare-step>
The step inspects the documents on port source in turn to create the resulting
  map:
- 
    If the document under inspection is a JSON document representing a map, all key-value pairs are copied into the result map unless this map already contains an entry with the given key. In this case the value of option duplicatesdetermines the policy for handling duplicate keys as specified for functionmap:mergein [XPath and XQuery Functions and Operators 3.1]. It is a dynamic error (err:XC0106) if duplicate keys are encountered and optionduplicateshas value “reject”.
- 
    For every other type of JSON document, for XML documents, HTML documents, or text documents a new key-value pair is created and put into the resulting map. The key is created by evaluating the XPath expression in option keywith the inspected document as context item. If the evaluation result is a single atomic value, it is taken as key. If the evaluation result is a node, its string value is taken as key. It is a dynamic error (err:XC0110) if the evaluation of the XPath expression in optionkeyfor a given item returns either a sequence, an array, a map, or a function. Duplicate keys are handled as described above. The XDM representation of the inspected document is taken as value of the key-value pair.
- 
    It is implementation defined if p:json-mergeis able to process document types not mentioned yet, i.e. types of binary documents. If a processor supports a given type of documents, the key-value pair is created as described above. It is a dynamic error (err:XC0107) if a document of a not supported document type appears on portsourceofp:json-merge.
An implementation must bind the variable “p:index” in the static context of 
    each evaluation of the XPath expression to the position of the document in the sequence 
    of documents on port source, starting with “1”.
    
Document properties
No document properties are preserved.
The merged document has no base-uri.
The p:label-elements step generates a label for each matched
element and stores that label in the specified attribute.
<p:declare-step type="p:label-elements">
     <p:input port="source" content-types="xml html"/>
     <p:output port="result" content-types="xml html"/>
     <p:option name="attribute" as="xs:QName" select="'xml:id'"/>  
     <p:option name="label" as="xs:string" select="'concat("_",$p:index)'"/><!-- XPathExpression -->
     <p:option name="match" as="xs:string" select="'*'"/>          <!-- XSLTSelectionPattern -->
     <p:option name="replace" as="xs:boolean" select="true()"/>    </p:declare-step>
The value of the label option is an XPath
expression used to generate the value of the attribute label.
The value of the match option
must be an XSLTSelectionPattern. It
is a dynamic error (err:XC0023) if that expression matches
anything other than element nodes.
The value of the replace
must be a boolean value and is used to indicate
whether existing attribute values are replaced.
This step operates by generating attribute labels for each
element matched. For every matched element, the expression is
evaluated with the context node set to the matched element. An
attribute is added to the matched element using the attribute name is
specified the attribute option and the string value
of result of evaluating the expression. If the attribute already
exists on the matched element, the value is replaced with the string
value only if the replace option has the value of
true.
If this step is used to add or change the value
of an attribute named “xml:base”, the base URI
of the element must also be amended accordingly.
An implementation must bind the variable
“p:index” in the static context of each evaluation
of the XPath expression to the position of the element in the sequence
of matched elements. In other words, the first element (in document
order) matched gets the value “1”, the second gets
the value “2”, the third, “3”,
etc.
The result of the p:label-elements step is the input document with the attribute labels associated with matched elements. All other non-matching content remains the same.
Document properties
All document properties are preserved.
The p:load step has no inputs but produces as its
result a document specified by an IRI.
<p:declare-step type="p:load">
     <p:output port="result" content-types="any"/>
     <p:option name="href" required="true" as="xs:anyURI"/>        
     <p:option name="parameters" as="map(xs:QName,item()*)?"/>     
     <p:option name="content-type" as="xs:string?"/>               
     <p:option name="document-properties" as="map(xs:QName, item()*)?"/></p:declare-step>
If the option is relative, it
    is made absolute against the base URI of the element on which it is specified
      (p:with-option or the step in case of a syntactic shortcut value). If the
      href is relative, it is made absolute against the base URI of the element on
    which it is specified (p:with-option or p:load in the case of a syntactic
    shortcut value). It is a dynamic 
      error (err:XD0064) if the base URI is not both absolute and valid according to [RFC 3986].
The document identified by the
href URI is loaded and returned. If the URI protocol
supports redirection, then redirects must be
followed.
It is a dynamic error (err:XD0011)
if the resource referenced by a p:load element does not exist
or cannot be accessed.
The behavior of this step depends on the content type of the document loaded. The content type of a document is determined as follows:
- 
If a content-typeproperty is specified indocument-propertiesorcontent-typeis present, then the document must be interpreted according to that content type. It is a dynamic error (err:XD0079) if a supplied content-type is not a valid media type of the form “type/subtype+exttype/subtypeerr:XD0062) if thecontent-typeis specified and the document-properties has a “content-type” that is not the same.
- 
If the document is retrieved with a URI protocol that specifies a content type (for example, http:), then the document must be interpreted according to that content type.
- 
In the absence of an explicit type, the content type is implementation-defined. 
The parameters map contains additional, optional
parameters that may influence the way that content is loaded. The interpretation
of this map varies according to the content type. Parameter names that are in
no namespace are treated as strings using only the local-name where appropriate.
Broadly speaking, there are five categories of data that might be loaded: XML, text, JSON, HTML, and “other” binary data.
For an XML media type, the content is loaded and parsed as XML.
It is a dynamic error (err:XD0049) if
the loaded content is not a well-formed XML document.
If the dtd-validate parameter is true,
then DTD validation must be performed when parsing the document.
It is a dynamic error (err:XD0023) if a DTD validation
is performed and either the document is not valid or no DTD is found.
It is a dynamic error (err:XD0043)
if the dtd-validate parameter is true and
the processor does not support DTD validation.
Additional XML parameters are implementation-defined.
For a text media type, the content is loaded as a text document. (A text document is an XPath data model document consisting of a single text node.)
It is a dynamic error (err:XD0060) if the
content-type specifies an encoding, which is not supported
by the processor.
Text parameters are implementation-defined.
For a JSON media type, the content is loaded and parsed as JSON.
The parameters specified for the fn:parse-json function
in [XPath and XQuery Functions and Operators 3.1]
must be supported.
Additional JSON parameters are implementation-defined.
It is a dynamic error (err:XD0057) if the loaded content
does not conform to the JSON grammar, unless the parameter liberal is
true and the processor chooses to accept the deviation.
It is a dynamic error (err:XD0058) if the parameter
duplicates is reject and the value of
loaded content contains a JSON object with duplicate keys.
It is a dynamic error (err:XD0059) if the parameter
map contains an entry whose key is defined in the specification of
fn:parse-json and whose value is not valid for that key, or if it contains
an entry with the key fallback when the parameter escape with
true() is also present.
For an HTML media type, the content is loaded and parsed into an XPath data model document that contains a tree of elements, attributes, and other nodes.
The precise way in which HTML documents are parsed into the XPath data model is implementation-defined.
It is a dynamic error (err:XD0078)
if the loaded document cannot be represented as an HTML document in
the XPath data model.
HTML parameters are implementation-defined.
An XProc processor may load other, arbitrary data types. How a processor interprets other media types is implementation-defined.
Parameters for other media types are implementation-defined.
Document properties
The properties specified in document-properties are applied.
If the properties do not specify a base-uri, the 
base-uri property will reflect the base URI of the loaded document.
The p:make-absolute-uris step makes an element or
attribute's value in the source document an absolute IRI value in the
result document.
<p:declare-step type="p:make-absolute-uris">
     <p:input port="source" content-types="xml html"/>
     <p:output port="result" content-types="xml html"/>
     <p:option name="match" required="true" as="xs:string"/>       <!-- XSLTSelectionPattern -->
     <p:option name="base-uri" as="xs:anyURI?"/>                   </p:declare-step>
The value of the match option must be an
XSLTSelectionPattern.
It is a dynamic error (err:XC0023) if
the pattern matches anything other than element or attribute
nodes.
The value of the base-uri option
must be an anyURI. It is interpreted
as an IRI reference. If it is relative, it is made absolute against
the base URI of the element on which it is specified
(p:with-option or p:make-absolute-uris in the case of
  a syntactic shortcut value). It is a dynamic 
    error (err:XD0064) if the base URI is not both absolute and valid according to [RFC 3986].
For every element or attribute in the input document which matches the specified pattern, its XPath string-value is resolved against the specified base URI and the resulting absolute IRI is used as the matched node's entire contents in the output.
The base URI used for resolution defaults to the matched
attribute's element or the matched element's base URI unless the
base-uri option is specified. When the
base-uri option is specified, the option value is
used as the base URI regardless of any contextual base URI value in
the document. This option value is resolved against the base URI of
the p:option element used to set the option.
If the IRI reference specified by the base-uri option
on p:make-absolute-uris is absent and the input document has no base URI,
the results are implementation-dependent.
Document properties
All document properties are preserved.
The p:namespace-delete step deletes all of the namespaces identified by the specified 
      prefixes from the document appearing on port source.
<p:declare-step type="p:namespace-delete">
     <p:input port="source" content-types="xml html"/>
     <p:output port="result" content-types="xml html"/>
     <p:option name="prefixes" required="true" as="xs:string"/>    </p:declare-step>
The value of option prefixes is taken as a space separated list of
prefixes. It is a dynamic error (err:XC0108) if any
prefix is not in-scope at the point where the p:namespace-delete occurs.
For any prefix the associated namespace is removed from the elements and 
attributes in the document appearing on port source. The respective
elements or attributes in the document appearing on port result will be
in no namespace.
It is a dynamic error (err:XC0109) if
a namespace is to be removed from an attribute and the element already has an attribute
with the resulting name.
Document properties
All document properties are preserved.
The p:namespace-rename step renames any namespace declaration or
use of a namespace in a document to a new IRI value.
<p:declare-step type="p:namespace-rename">
     <p:input port="source" content-types="xml html"/>
     <p:output port="result" content-types="xml html"/>
     <p:option name="from" as="xs:anyURI?"/>                       
     <p:option name="to" as="xs:anyURI?"/>                         
     <p:option name="apply-to" as="xs:token" select="'all'" values="('all','elements','attributes')"/></p:declare-step>
The value of the from option
must be an anyURI. It
should be either empty or absolute, but will not be
resolved in any case.
The value of the to option
must be an anyURI. It
should be empty or absolute, but will not be
resolved in any case.
The value of the apply-to option
must be one of “all”,
“elements”, or “attributes”.
If the value is “elements”, only elements will be
renamed, if the value is “attributes”, only attributes
will be renamed, if the value is “all”, both elements
and attributes will be renamed.
It is a dynamic error (err:XC0014)
if the XML namespace (http://www.w3.org/XML/1998/namespace)
or the
XMLNS namespace (http://www.w3.org/2000/xmlns/) is
the value of either the from option or the
to option.
If the value of the from option is the same as
the value of the to option, the input is reproduced
unchanged on the output. Otherwise, namespace bindings, namespace
attributes and element and attribute names are changed as
follows:
- 
   Namespace bindings: If the fromoption is present and its value is not the empty string, then every binding of a prefix (or the default namespace) in the input document whose value is the same as the value of thefromoption is- 
     replaced in the output with a binding to the value of the tooption, provided it is present and not the empty string;
- 
     otherwise (the tooption is not specified or has an empty string as its value) absent from the output.
 If the fromoption is absent, or its value is the empty string, then no bindings are changed or removed.
- 
     
- 
   Elements and attributes: If the fromoption is present and its value is not the empty string, for every element and attribute, as appropriate, in the input whose namespace name is the same as the value of thefromoption, in the output its namespace name is- 
     replaced with the value of the tooption, provided it is present and not the empty string;
- 
     otherwise (the tooption is not specified or has an empty string as its value) changed to have no value.
 If the fromoption is absent, or its value is the empty string, then for every element and attribute, as appropriate, whose namespace name has no value, in the output its namespace name is set to the value of thetooption.It is a dynamic error ( err:XC0092) if as a consequence of changing or removing the namespace of an attribute the attribute's name is not unique on the respective element.
- 
     
- 
   Namespace attributes: If the fromoption is present and its value is not the empty string, for every namespace attribute in the input whose value is the same as the value of thefromoption, in the output- 
     the namespace attribute's value is replaced with the value of the tooption, provided it is present and not the empty string;
- 
     otherwise (the tooption is not specified or has an empty string as its value) the namespace attribute is absent.
 
- 
     
Note
The apply-to option is primarily intended to make
it possible to avoid renaming attributes when the from option
specifies no namespace, since many attributes are in no namespace.
Care should be taken when specifying no namespace with the
to option.  Prefixed names in content, for example QNames and
XPath expressions, may end up with no appropriate namespace binding.
Document properties
All document properties are preserved.
The p:pack step merges two document sequences in a pair-wise
fashion.
<p:declare-step type="p:pack">
     <p:input port="source" content-types="text xml html" sequence="true" primary="true"/>
     <p:input port="alternate" sequence="true" content-types="text xml html"/>
     <p:output port="result" sequence="true" content-types="application/xml"/>
     <p:option name="wrapper" required="true" as="xs:QName"/>      </p:declare-step>
The step takes each pair of documents, in order, one from the
source port and one from the alternate port,
wraps them with a new element node whose QName is the value specified
in the wrapper option, and writes that element to the
result port as a document.
If the step reaches the end of one input sequence before the other, then it simply wraps each of the remaining documents in the longer sequence.
Note
In the common case, where the document element of a document in
the result sequence has two element children, any
comments, processing instructions, or white space text nodes that
occur between them may have come from either of the input documents;
this step does not attempt to distinguish which one.
Document properties
No document properties are preserved.
The result documents do not have a base-uri property.
The p:rename step renames elements, attributes, or
processing-instruction targets in a document.
<p:declare-step type="p:rename">
     <p:input port="source" content-types="xml html"/>
     <p:output port="result" content-types="xml html"/>
     <p:option name="match" as="xs:string" select="'/*'"/>         <!-- XSLTSelectionPattern -->
     <p:option name="new-name" required="true" as="xs:QName"/>     </p:declare-step>
The value of the match option must be an
XSLTSelectionPattern. It is a dynamic
error (err:XC0023) if the pattern matches anything other than element,
attribute or processing instruction nodes.
Each element, attribute, or processing-instruction in the input
matched by the selection pattern specified in the match
option is renamed in the output to the name specified by the
new-name option.
If the match option matches an attribute and if
the element on which it occurs already has an attribute whose expanded
name is the same as the expanded name of the specified
new-name, then the results is as if the current
attribute named “new-name” was deleted before
renaming the matched attribute.
With respect to attributes named “xml:base”, the
following semantics apply: renaming an from
“xml:base” to something else has
no effect on the underlying base URI of the element; however,
if an attribute is renamed from something else
to “xml:base”, the base URI
of the element must also be amended accordingly.
If the pattern matches processing instructions, then it is the
processing instruction target that is renamed. It
is a dynamic error (err:XC0013) if the pattern matches
a processing instruction and the new name has a non-null namespace.
Document properties
All document properties are preserved.
The p:replace step replaces matching nodes in
its primary input with the top-level node(s) of the
replacement port's document.
<p:declare-step type="p:replace">
     <p:input port="source" primary="true" content-types="xml html"/>
     <p:input port="replacement" content-types="text xml html"/>
     <p:output port="result" content-types="text xml html"/>
     <p:option name="match" required="true" as="xs:string"/>       <!-- XSLTSelectionPattern --></p:declare-step>
The value of the match option
must be an XSLTSelectionPattern. It
is a dynamic error (err:XC0023) if that pattern matches
an attribute or a namespace nodes.  Multiple matches are allowed, in which case multiple
copies of the replacement document will occur.
Every node in the primary input matching the specified
pattern is replaced in the output by the top-level node(s)
of the replacement document. Only non-nested matches are
replaced. That is, once a node is replaced, its descendants cannot
be matched.
If the document node is matched and port replacement contains
a text document, the entire document is replaced by the text node. What appears on port 
result is a text document with the text node wrapped in a document node.
Document properties
If the resulting document contains exactly one text node,
the content-type property is changed to text/plain and the 
   serialization property is removed, while all other document properties are 
   preserved. For other document types, all document properties are preserved.
The p:set-attributes step sets attributes on
matching elements.
<p:declare-step type="p:set-attributes">
     <p:input port="source" primary="true" content-types="xml html"/>
     <p:output port="result" content-types="xml html"/>
     <p:option name="match" as="xs:string" select="'/*'"/>         <!-- XSLTSelectionPattern -->
     <p:option name="attributes" required="true" as="map(xs:QName, xs:anyAtomicType)"/></p:declare-step>
The value of the match option must be an
 XSLTSelectionPattern. It is a dynamic
 error (err:XC0023) if that pattern matches anything other than element
 nodes.
A new attribute is created for each entry in the map appearing
on the attributes option. The attribute name is taken
from the entry's key while the attribute value is taken from the string value of
the entry's value.
If an attribute with the same name as one of the attributes to
be created already exists, the value specified on the
attributes option is used. The result port of
this step produces a copy of the source port's document
with the matching elements' attributes modified.
The matching elements are specified by the selection pattern in the
match option. All matching elements are processed.
If no elements match, the step will not change any elements.
If the attributes taken from the attributes use namespaces, 
prefixes, or prefixes bound to different namespaces, the document produced on the
result output port will require namespace fixup.
If an attribute named
xml:base is added or changed, the base URI
of the element must also be amended accordingly.
Document properties
All document properties are preserved.
The p:set-properties step sets document
properties on the source document.
<p:declare-step type="p:set-properties">
     <p:input port="source" content-types="any"/>
     <p:output port="result" content-types="any"/>
     <p:option name="properties" required="true" as="map(xs:QName,item()*)"/>
     <p:option name="merge" select="true()" as="xs:boolean"/>      </p:declare-step>
The document properties of the document
on the source port are augmented with the values specified
in the properties option. The document produced on
the result port has the same representation but the
adjusted property values.
If the merge
option is true, then the supplied properties are added to the existing
properties, overwriting already existing values for a given key. 
If it is false, the document’s properties are replaced by
the new set.
It is a dynamic error (err:XD0070) if a value is 
assigned to the serialization document property that cannot be converted 
into map(xs:QName, item()*) according
to the rules in section “QName handling” of [XProc 3.0].
It is a dynamic
error (err:XC0069) if the properties map contains
a key equal to the string “content-type”.
If the properties map contains a key equal to the string
“base-uri” the associated value is taken as the new base URI of
   the resulting document. It is a dynamic 
   error (err:XD0064) if the base URI is not both absolute and valid according 
      to [RFC 3986].
Document properties
If merge is true, document 
properties not overridden by settings in the properties map are preserved, 
otherwise the resulting document has only the content-type property and the
properties specified in the properties map. In particular, if merge 
is false, the base-uri property will not be preserved. This means that the resulting
document will not have a base URI if the properties map does not contain 
a base-uri entry.
The p:sink step accepts a sequence of documents and
discards them. It has no output.
<p:declare-step type="p:sink">
     <p:input port="source" content-types="any" sequence="true"/></p:declare-step>
Document properties
Not applicable.
The p:split-sequence step accepts a sequence of
documents and divides it into two sequences.
<p:declare-step type="p:split-sequence">
     <p:input port="source" content-types="any" sequence="true"/>
     <p:output port="matched" sequence="true" primary="true" content-types="any"/>
     <p:output port="not-matched" sequence="true" content-types="any"/>
     <p:option name="initial-only" as="xs:boolean" select="false()"/>
     <p:option name="test" required="true" as="xs:string"/>        <!-- XPathExpression --></p:declare-step>
The value of the test option must be an XPathExpression.
The XPath expression in the test option is
applied to each document in the input sequence. If the effective
boolean value of the expression is true, the document is copied to the
matched port; otherwise it is copied to the
not-matched port.
If the initial-only option is true, then when
the first document that does not satisfy the test expression is
encountered, it and all the documents that follow
it are written to the not-matched port.
In other words, it only writes the initial series of matched
documents (which may be empty) to the matched port.
All other documents are written to the not-matched port,
irrespective of whether or not they match.
The XPath context for the
test option changes over time. For each document that
appears on the source port, the expression is evaluated
with that document as the context document. The context position
(position()) is the position of that document within the
sequence and the context size (last()) is the total
number of documents in the sequence. It is a 
dynamic error (err:XC0150) if evaluating the XPath expression
in option test on a context document results
in an error.
Note
In principle, this component cannot stream because it must
buffer all of the input sequence in order to find the context size. In
practice, if the test expression does not use the
last() function, the implementation can stream
and ignore the context size.
If the implementation supports passing PSVI annotations between
steps, the p:split-sequence step must preserve
any annotations that appear in the input.
Document properties
All document properties are preserved.
The p:store step stores (a possibly serialized
version of) its input to a URI. It outputs a reference to the location
of the stored document on the result-uri port.
Aside from these side-effects, it behaves like a p:identity
step, copying its input to the result port.
<p:declare-step type="p:store">
     <p:input port="source" content-types="any"/>
     <p:output port="result" content-types="any" primary="true"/>
     <p:output port="result-uri" content-types="application/xml"/>
     <p:option name="href" required="true" as="xs:anyURI"/>        
     <p:option name="serialization" as="map(xs:QName,item()*)?"/>  </p:declare-step>
The value of the href option
must be an anyURI. If it is relative,
it is made absolute against the base URI of the element on which it is
specified (p:with-option or p:store in the case
of a syntactic shortcut
value).
The step attempts to store the document to the specified
  URI. If the URI scheme “file:” is supported, the processor
 should try to create all non existing folders in the URI’s path. 
It is a dynamic error (err:XC0050)
if the URI scheme is not supported or the step cannot store to the
specified location.
The output of this step on the result-uri port is a 
document containing a single c:result element whose content 
is the absolute URI of the document stored by the step.
The serialization option is provided to control the
serialization of content when it is stored. If the document to be stored
has a “serialization” property, the serialization is controlled by the
merger of the two maps where the entries in the “serialization” property
take precedence. Serialization is described in
[XProc 3.0].
Document properties
All document properties are preserved.
The p:string-replace step matches nodes in the
document provided on the source port and replaces them
with the string result of evaluating an XPath expression.
<p:declare-step type="p:string-replace">
     <p:input port="source" content-types="xml html"/>
     <p:output port="result" content-types="text xml html"/>
     <p:option name="match" required="true" as="xs:string"/>       <!-- XSLTSelectionPattern -->
     <p:option name="replace" required="true" as="xs:string"/>     <!-- XPathExpression --></p:declare-step>
The value of the match option must be an
XSLTSelectionPattern.
The value of the replace option must be an
XPathExpression.
The matched nodes are specified with the selection pattern in the
match option.
For each matching node, the XPath
expression provided by the replace option is
evaluated with the matching node as the XPath context node.
The string value of the result is used in the output.
Nodes that do not match are copied without change.
If the expression given in the match option
matches an attribute, the string value of the
replace
expression is used as the new value of the attribute in the output.
If the attribute is named “xml:base”, the base URI
of the element must also be amended accordingly.
If the document node is matched, the entire document is replaced by the string
value of the replace expression. What appears on port result 
is a text document with the text node wrapped in a document node.
If the expression matches any other kind of node, the entire
node (and not just its contents) is replaced by
the string value of the replace expression.
Document properties
If the resulting document contains exactly one text node,
      the content-type property is changed to text/plain and the 
      serialization property is removed, while all other document properties are 
      preserved. For other document types, all document properties are preserved.
The p:text-count step counts the number of lines in a text document and returns a single XML
    document containing that number.
<p:declare-step type="p:text-count">
     <p:input port="source" primary="true" sequence="false" content-types="text"/>
     <p:output port="result" primary="true" sequence="false" content-types="application/xml"/></p:declare-step>
The p:text-count step counts the number of lines in the text document appearing on its
      source port. It returns on its result port an XML document containing a single
      c:result element whose contents is the string representing this count.
Lines are identified as described in XML, 2.11 End-of-Line Handling. For the purpose of identifying lines, if the very last character in the text document is a newline (
), that newline is ignored. (It is not a separator between that line and a following line that contains no characters.)
Document properties
No document properties are preserved.
The count document does not have a base-uri property.
The p:text-head step returns lines from the beginning of a text document.
<p:declare-step type="p:text-head">
     <p:input port="source" primary="true" sequence="false" content-types="text"/>
     <p:output port="result" primary="true" sequence="false" content-types="text"/>
     <p:option name="count" required="true" as="xs:integer"/>      </p:declare-step>
The p:text-head step returns on its result port lines from the text document that
    appears on its source port:
- 
      If the countoption is positive, thep:text-headstep returns the firstcountlines
- 
      If the countoption is zero, thep:text-headstep returns all lines
- 
      If the countoption is negative, thep:text-headstep returns all lines except the firstcountlines
Lines are identified as described in XML, 2.11
      End-of-Line Handling.
All lines returned by p:text-head are terminated with a single
newline (
).
Document properties
All document properties are preserved.
The p:text-join step concatenates text documents.
<p:declare-step type="p:text-join">
     <p:input port="source" sequence="true" content-types="text"/>
     <p:output port="result" content-types="text"/>
     <p:option name="separator" as="xs:string?"/>                  
     <p:option name="prefix" as="xs:string?"/>                     
     <p:option name="suffix" as="xs:string?"/>                     
     <p:option name="override-content-type" as="xs:string?"/>      </p:declare-step>
The p:text-join step concatenates the text documents appearing on its source port
    into a single document on its result port. The documents will be concatenated in order of appearance. 
- 
      When the separatoroption is specified, its value will be inserted in between adjacent documents.
- 
      When the prefixoption is specified, the document appearing on theresultport will always start with its value (also when there are no documents on thesourceport).
- 
      When the suffixoption is specified, the document appearing on theresultport will always end with its value (also when there are no documents on thesourceport).
When the override-content-type option is specified, the document appearing on the port result
    will have this media type as part of its document properties. It is a dynamic 
      error (err:XD0079) if a supplied content-type is not  a valid media type of the form 
      “type/subtype+exttype/subtypeerr:XC0001) if the value of option override-content-type 
      is not a text media type.
  
Concatenating text documents does not require identifying individual lines in each document, consequently no special end-of-line handling is performed.
Document properties
No document properties are preserved.
The joined document has no base-uri property.
The p:text-replace step replaces all occurrences of substrings in a text document that match a
    supplied regular expression with a given replacement string.
<p:declare-step type="p:text-replace">
     <p:input port="source" primary="true" sequence="false" content-types="text"/>
     <p:output port="result" primary="true" sequence="false" content-types="text"/>
     <p:option name="pattern" required="true" as="xs:string"/>     
     <p:option name="replacement" required="true" as="xs:string"/> 
     <p:option name="flags" as="xs:string?"/>                      </p:declare-step>
The p:text-replace step replaces all occurrences of substrings in the text document appearing on
    its source port that match a supplied regular expression with a given replacement string. The result is
    returned (as another text document) on its result port. 
This step is a convenience wrapper around the XPath fn:replace
    function to ease text replacements in the document flow of a pipeline.
The pattern, replacement and flags
    options are specified the same as the parameters with the same names of the fn:replace function. The pattern option
      must be a regular expression as specified in [XPath and XQuery Functions and Operators 3.1], section 7.61 “Regular Expression Syntax”.
      It is a dynamic error (err:XC0147) if the specified value is not
      a valid XPath regular expression.
Replacing strings in text documents does not require identifying individual lines in each document, consequently no special end-of-line handling is performed.
Document properties
All document properties are preserved.
The p:text-sort step sorts lines in a text document.
<p:declare-step type="p:text-sort">
     <p:input port="source" primary="true" sequence="false" content-types="text"/>
     <p:output port="result" primary="true" sequence="false" content-types="text"/>
     <p:option name="sort-key" as="xs:string" select="'.'"/>       <!-- XPathExpression -->
     <p:option name="order" as="xs:string" select="'ascending'" values="('ascending', 'descending')"/>
     <p:option name="case-order" as="xs:string?" values="('upper-first', 'lower-first')"/>
     <p:option name="lang" as="xs:language?"/>                     
     <p:option name="collation" as="xs:string" select="'https://www.w3.org/2005/xpath-functions/collation/codepoint'"/>
     <p:option name="stable" as="xs:boolean" select="true()"/>     </p:declare-step>
The p:text-sort step sorts the lines in the text document appearing on its source port
    and returns the result as another text document on its result port. The sort key is obtained by applying
    the XPath expression in sort-key to each line in turn.
- 
      The sort-keyis used to obtain a sort key for each of the lines in the document appearing onsource. Thecontext itemis the line as an instance ofxs:string, thecontext positionis the number of the line in the document on portsource, thecontext sizeis the number of lines in this document. It is a dynamic error (err:XC0098) if a dynamic XPath error occurred while applying sort-key to a line. It is a dynamic error (err:XC0099) if the result of applyingsort-keyto a given line results in a sequence with more than one item.
- 
     The orderoption defines whether the lines are processed in ascending or descending order. Its value must be one ofascendingordescending. The default isascending.
- 
      The case-orderoption defines whether upper-case letters are to be collated before or after lower-case letters. Its value must be one ofupper-firstorlower-first. The default is language-dependent.
- 
      The langoption defines the language whose collating conventions are to be used. The default depends on the processing environment. Its value must be a valid language code (e.g.en-EN).
- 
      The collationoption identifies how strings are to be compared with each other. Its value must be a valid collation URI. The only collation XProc processors must support is the Unicode Codepoint Collationhttp://www.w3.org/2005/xpath-functions/collation/codepoint. This is also its default. Support for other collations is implementation-defined.
- 
      If the stableoption is set tofalsethis indicates that there is no requirement to retain the original order of items that have equal values for all the sort keys.
Lines are identified as described in XML, 2.11
      End-of-Line Handling.
For the purpose of identifying lines, if the very last character in the text
document is a newline (
), that newline is ignored. (It is not a separator
between that line and a following line that contains no characters.)
All lines returned by p:text-sort are terminated with a single
newline (
).
The sort process performed by this step is the same as described in 
    The xsl:sort Element. Options lang
    and case-order are only taken into consideration if no value is selected for option
    collation.
Document properties
All document properties are preserved.
The p:text-tail step returns lines from the end of a text document.
<p:declare-step type="p:text-tail">
     <p:input port="source" primary="true" sequence="false" content-types="text"/>
     <p:output port="result" primary="true" sequence="false" content-types="text"/>
     <p:option name="count" required="true" as="xs:integer"/>      </p:declare-step>
The p:text-tail step returns on its result port lines from the text document that
    appears on its source port:
- 
      If the countoption is positive, thep:text-tailstep returns the lastcountlines
- 
      If the countoption is zero, thep:text-tailstep returns all lines
- 
      If the countoption is negative, thep:text-tailstep returns all lines except the lastcountlines
Lines are identified as described in XML, 2.11
    End-of-Line Handling.
All lines returned by p:text-tail are terminated with a single
newline (
).
Document properties
All document properties are preserved.
The p:unarchive step outputs on its result port specific entries
    in an archive (for instance from a zip file).
<p:declare-step type="p:unarchive">
     <p:input port="source" primary="true" content-types="any" sequence="false"/>
     <p:output port="result" primary="true" content-types="any" sequence="true"/>
     <p:option name="include-filter" as="xs:string*"/>             <!-- RegularExpression -->
     <p:option name="exclude-filter" as="xs:string*"/>             <!-- RegularExpression -->
     <p:option name="format" as="xs:QName?"/>                      
     <p:option name="parameters" as="map(xs:QName, item()*)?"/>    
     <p:option name="relative-to" as="xs:anyURI?"/>                
     <p:option name="override-content-types" as="array(array(xs:string))?"/></p:declare-step>
The meaning and interpretation of the p:unarchive step's options is as
    follows:
- 
      The format of the archive is determined as follows: - 
          If the formatoption is specified, this determines the format of the archive. Implementations must support the [ZIP] format, specified with the valuezip. It is implementation-defined what other formats are supported.
- 
          If no formatoption is specified or if its value is the empty sequence, the archive's format will be determined by the step, using thecontent-typedocument-property of the document on thesourceport and/or by inspecting its contents. It is implementation-defined how the step determines the archive's format. Implementations should recognize archives in [ZIP] format.
- It is a dynamic error ( - err:XC0085) if the format of the archive does not match the specified format, cannot be understood, determined and/or processed.
 
- 
          
- 
      The parametersoption can be used to supply parameters to control the unarchiving. The semantics of the keys and the allowed values for these keys are implementation-defined. It is a dynamic error (err:XC0079) if the mapparameterscontains an entry whose key is defined by the implementation and whose value is not valid for that key.
- 
      If present, the value of the include-filterorexclude-filteroption must be a sequence of strings, each one representing a regular expressions as specified in [XPath and XQuery Functions and Operators 3.1], section 7.61 “Regular Expression Syntax”. It is a dynamic error (err:XC0147) if a specified value is not a valid XPath regular expression.If neither the include-filteroption nor theexclude-filteroption is specified, thep:unarchivestep outputs on itsresultport all entries in the archive.If the include-filteroption or theexclude-filteroption is specified, thep:archivestep outputs on theresultport the entries from the archive that conform to the following rules:- 
          If any include-filterpattern matches an archive entry's name, the entry is included in the output.
- 
          If any exclude-filterpattern matches an archive entry's name, the entry is excluded in the output.
- 
          If both options are provided, the include filter is processed first, then the exclude filter. 
- 
          Names of entries in archives are always relative names. For instance, the name of a file called xyz.xmlin aspecssubdirectory in an archive is called in fullspecs/xyz.xml(and not/specs/xyz.xml).
 As a result: an item is included if it matches (at least) one of the include-filtervalues and none of theexclude-filtervalues.The regular expressions specified in the include-filterandexclude-filteroptions will be matched against the path of the entry in the archive. The matching is done unanchored: it is a match if the regular expression matches part of the entry's path. Informally: matching behaves like applying the XPathmatches#2function, like inmatches($path-in-archive, $regular-expression).NoteDepending on how archives are constructed, the path of an entry in an archive can be with or without a leading slash. Usually it will be without. For archives constructed by p:archiveno leading slash will be present.
- 
          
- 
      The relative-tooption, when present, is used in creating the base URI of the unarchived documents. If the option is relative, it is made absolute against the base URI of the element on which it is specified (p:with-optionor the step in case of a syntactic shortcut value).
- 
      The override-content-typesoption can be used to partially override the content-type determination mechanism, as described in Section 2.4.1, “Overriding content types”.
The base URI of an unarchived document appearing on the result port is: 
- 
      If the relative-tooption is present: Functionp:urify()is called with the value of this option as second parameter ($basedir) and with the relative path of this document as it was in the archive as first parameter
- 
      If the relative-tooption is not present: Functionp:urify()is called with the value of the base URI of the archive appended with a “/” as second parameter ($baseDir) and the relative path of this document as it was in the archive as first parameter
It is a dynamic error (err:XC0120) if the 
    relative-to option is not present and the document on the 
    source port does not have a base URI.
    It is a dynamic
    error (err:XD0064) if the option is not a valid URI according to [RFC 3986].
For instance, the base URI of an unarchived file called xyz.xml that resided in
    the specs subdirectory in an archive with base URI file:///a/b/c.zip
    will become: 
- 
      With the relative-tooption set tofile:///x/y/z:file:///x/y/z/specs/xyz.xml
- 
      Without a relative-tooption set:file:///a/b/c.zip/specs/xyz.xml
Document properties
No document properties are preserved.
The base-uri property of each unarchived document is reflective of
the base URI of the document.
The p:uncompress step expects on its source port a compressed
    document. It outputs an uncompressed version of this on its result port.
<p:declare-step type="p:uncompress">
     <p:input port="source" primary="true" content-types="any" sequence="false"/>
     <p:output port="result" primary="true" content-types="any" sequence="false"/>
     <p:option name="format" as="xs:QName?"/>                      
     <p:option name="parameters" as="map(xs:QName,item()*)?"/>     
     <p:option name="content-type" as="xs:string" select="'application/octet-stream'"/></p:declare-step>
The compression format of the document appearing on the source port is
    determined as follows:
- 
      If the formatoption is specified, this determines the compression format. Implementations must support the [GZIP] format, specified with the valuegzip. It is implementation-defined what other formats are supported. It is a dynamic error (err:XC0202) if the compression format cannot be understood, determined and/or processed.
- 
      If no formatoption is specified or its value is the empty sequence, the compression format will be determined by the step, using thecontent-typedocument-property of the document on thesourceport and/or by inspecting its contents. It is implementation-defined how the step determines the compression format. Implementations should recognize archives in [GZIP] format.
The parameters option can be used to supply parameters to control the
    uncompression. The semantics of the keys and the allowed values for these keys are
      implementation-defined.
    It is a dynamic error (err:XC0079) if the map
      parameters contains an entry whose key is defined by the
      implementation and whose value is not valid for that key.
Identification of the uncompressed document's content-type is done as follows:
- 
      If the content-typeoption is specified, the uncompressed document must be interpreted according to that content-type. It is a dynamic error (err:XD0079) if a supplied content-type is not a valid media type of the form “type/subtype+exttype/subtypeerr:XC0201) if thep:uncompressstep cannot perform the requested content-type cast.
- 
      In the absence of an explicit type, the content will be interpreted as content type application/octet-stream.
Document properties
All document properties are preserved, except for the
        content-type property which is updated accordingly.
The p:unwrap step replaces matched elements with their
children.
<p:declare-step type="p:unwrap">
     <p:input port="source" content-types="xml html"/>
     <p:output port="result" content-types="application/xml text/plain"/>
     <p:option name="match" as="xs:string" select="'/*'"/>         <!-- XSLTSelectionPattern --></p:declare-step>
The value of the match option must be an
 XSLTSelectionPattern. It is a dynamic
 error (err:XC0023) if that pattern matches anything other than the document node
 or element nodes.
Every element in the source document that matches
the specified match pattern is replaced by its children,
effectively “unwrapping” the children from their parent. Non-element nodes
and unmatched elements are passed through unchanged.
Note
The matching applies to the entire document, not just the “top-most”
matches. A pattern of the form h:div will replace
all h:div elements, not just the top-most
ones.
This step produces a single document; if the document element is
unwrapped, the result might not be well-formed XML. If the step produces a
document node with a single text child, the result will have content type 
“text/plain”.
Document properties
All document properties are preserved.
The p:uuid step generates a
[UUID] and injects it into
the source document.
<p:declare-step type="p:uuid">
     <p:input port="source" primary="true" content-types="xml html"/>
     <p:output port="result" content-types="text xml html"/>
     <p:option name="match" as="xs:string" select="'/*'"/>         <!-- XSLTSelectionPattern -->
     <p:option name="version" as="xs:integer?"/>                   </p:declare-step>
The value of the match option must be an
XSLTSelectionPattern. The value of the version option
must be an integer.
If the version is specified, that version of
UUID must be computed. It is a dynamic
error (err:XC0060) if the processor does not support the specified
version of the UUID algorithm. If the
version is not specified, the version of UUID
computed is
implementation-defined.
Implementations must support version 4 UUIDs. Support for other versions of UUID, and the mechanism by which the necessary inputs are made available for computing other versions, is implementation-defined.
The matched nodes are specified with the selection pattern in the
match option. For each matching node, the generated
UUID is used in the output (if more than one node matches, the
same UUID is used in each match). Nodes that do not
match are copied without change.
If the expression given in the match option
matches an attribute, the UUID is used as the new
value of the attribute in the output. If the attribute is named “xml:base”, the base URI of the element
must also be amended accordingly.
If the document node is matched, the entire document is replaced by a text node
with the UUID. What appears on port result is a text document with the
text node wrapped in a document node.
If the expression matches any other kind of node, the entire node (and not just its contents) is replaced by the UUID.
Document properties
If the resulting document contains exactly one text node,
    the content-type property is changed to text/plain and the 
    serialization property is removed, while all other document properties are 
    preserved. For other document types, all document properties are preserved.
The p:wrap-sequence step accepts a sequence of
documents and produces either a single document or a new sequence of
documents.
<p:declare-step type="p:wrap-sequence">
     <p:input port="source" content-types="text xml html" sequence="true"/>
     <p:output port="result" sequence="true" content-types="application/xml"/>
     <p:option name="wrapper" required="true" as="xs:QName"/>      
     <p:option name="group-adjacent" as="xs:string?"/>             <!-- XPathExpression --></p:declare-step>
The value of the group-adjacent option
must be an XPathExpression.
In its simplest form, p:wrap-sequence takes a
sequence of documents and produces a single, new document by placing
each document in the source sequence inside a new
document element as sequential siblings. The name of the document
element is the value specified in the wrapper
option.
The group-adjacent option can be used to group
adjacent documents.
The XPath context
for the
group-adjacent option changes over time. For each document that
appears on the source port, the expression is evaluated
with that document as the context document. The context position
(position()) is the position of that document within the
sequence and the context size (last()) is the total
number of documents in the sequence.
Whenever
two or more sequentially adjacent documents have the same “group
adjacent” value, they are wrapped together in a single wrapper
element.
Two “group adjacent” values are the same if the
standard XPath function deep-equal() returns true for them.
Document properties
No document properties are preserved.
The document produced has no base-uri property.
The p:wrap step wraps matching nodes in the
source document with a new parent element.
<p:declare-step type="p:wrap">
     <p:input port="source" content-types="xml html"/>
     <p:output port="result" content-types="application/xml"/>
     <p:option name="wrapper" required="true" as="xs:QName"/>      
     <p:option name="match" required="true" as="xs:string"/>       <!-- XSLTSelectionPattern -->
     <p:option name="group-adjacent" as="xs:string?"/>             <!-- XPathExpression --></p:declare-step>
The value of the match option
must be an XSLTSelectionPattern. It
is a dynamic error (err:XC0023) if the pattern matches
anything other than document, element, text, processing instruction, and comment
nodes.
The value of the group-adjacent option
must be an XPathExpression.
If the node matched is the document node (match="/"),
the result is a new document where the document element is a new
element node whose QName is the value specified in the
wrapper option. That new element contains copies of
all of the children of the original document node.
When the selection pattern does not match the document node,
every node that matches the specified match
pattern is replaced with a new element node whose QName is the value
specified in the wrapper option.
The content of that new element is a copy of the original,
matching node. The p:wrap step performs a "deep" wrapping, the children
of the matching node and their descendants are processed and wrappers
are added to all matching nodes.
The group-adjacent option can be used to group
adjacent matching nodes in a single wrapper element. The specified
XPath expression is evaluated for each matching node with that node
as the XPath context node. Whenever two or more adjacent matching nodes
have the same “group adjacent” value, they are wrapped together in
a single wrapper element. Two “group adjacent” values are the same if the
standard XPath function deep-equal() returns true for them.
Two matching nodes are considered adjacent if and only if they are siblings and either there are no nodes between them or all intervening, non-matching nodes are whitespace text, comment, or processing instruction nodes.
Document properties
All document properties are preserved.
The p:www-form-urldecode step decodes a
x-www-form-urlencoded string into a JSON representation.
<p:declare-step type="p:www-form-urldecode">
     <p:output port="result" content-types="application/json"/>
     <p:option name="value" required="true" as="xs:string"/>       </p:declare-step>
A JSON object of the form “map(xs:string, xs:string+)” will
appear on result port. The value option is interpreted 
as a string of parameter values encoded using the
x-www-form-urlencoded algorithm. Each name/value
pair is represented in the JSON object as key/value entry.
It is a
dynamic error (err:XC0037) if the value provided
is not a properly
x-www-form-urlencoded value.
If any parameter name occurs more than once in the encoded string, a sequence will be associated with the respective key. The order in the sequence retains the order of name/value pairs in the encoded string.
Document properties
The resulting JSON document has no properties 
  apart from content-type. In particular, it has no base-uri.
The p:www-form-urlencode step encodes a set of parameter
values as a x-www-form-urlencoded string.
<p:declare-step type="p:www-form-urlencode">
     <p:output port="result" content-types="text/plain"/>
     <p:option name="parameters" required="true" as="map(xs:string,xs:untypedAtomic+)"/></p:declare-step>
The map entries of parameters option are encoded as a single
x-www-form-urlencoded string of name/value pairs. This
string is returned on the result port as a text document.
If more than one value is associated with a given key in parameters
option, a name/value pair is created for each value.
Document properties
The resulting text document has no properties 
  apart from content-type. In particular, it has no base-uri.
The p:xinclude step applies [XInclude] processing to the source document.
<p:declare-step type="p:xinclude">
     <p:input port="source" content-types="xml html"/>
     <p:output port="result" content-types="xml html"/>
     <p:option name="fixup-xml-base" as="xs:boolean" select="false()"/>
     <p:option name="fixup-xml-lang" as="xs:boolean" select="false()"/></p:declare-step>
The value of the fixup-xml-base option must be a
boolean. If it is true, base URI fixup will be performed as per
[XInclude].
The value of the fixup-xml-lang option must be a
boolean. If it is true, language fixup will be performed as per
[XInclude].
The included documents are located with the base URI of the input document and are not provided as input to the step.
It is a dynamic error (err:XC0029)
if an XInclude error occurs during processing. 
Document properties
All document properties are preserved.
The p:xquery step applies an
XQuery query to the sequence of documents
provided on the source port.
<p:declare-step type="p:xquery">
     <p:input port="source" content-types="any" sequence="true" primary="true"/>
     <p:input port="query" content-types="text xml"/>
     <p:output port="result" sequence="true" content-types="any"/>
     <p:option name="parameters" as="map(xs:QName,item()*)?"/>     
     <p:option name="version" as="xs:string?"/>                    </p:declare-step>
If a sequence of documents is provided on the
source port, the first document is used as the
initial context item. The whole sequence is also the default
collection. If no documents are provided on the source port,
the initial context item is undefined and the default collection
is empty.
The query port must receive a single document which is either an XML
  document or a text document. A text document must be treated as
  the query. For an XML document the following rules apply:
- 
    If the document root element is c:query, the text descendants of this element are considered the query.<c:query>
 string
 </c:query>
- 
      If the document root element is in the XQueryX namespace, the document is treated as an XQueryX-encoded query. Support for XQueryX is implementation-defined. 
- 
      Otherwise the serialization of the document must be treated as the query. The document's serialization property (if present) is used. 
If the step specifies a version, then that version
of XQuery must be used to process the transformation.
It is a
dynamic error (err:XC0009) if the specified XQuery version
is not available. If the step does not specify a version, the
implementation may use any version it has available and may use any means
to determine what version to use, including, but not limited to,
examining the version of the query.It is implementation defined
which XQuery version(s) is/are supported.
The name/value pairs in option parameters are used to set the query’s
external variables.
It is a dynamic error (err:XC0101) if a document
appearing on port source cannot be represented in the XDM version associated with
  the chosen XQuery version, e.g. when a JSON document contains a map and XDM 3.0 is used. 
  It is a dynamic error (err:XC0102) if any key in option 
    parameters is associated to a value that cannot be represented in 
    the XDM version associated with the chosen XQuery version, e.g. with a map, an array, 
    or a function when XDM 3.0 is used.
It is a dynamic error (err:XC0103) if any error occurs during
    XQuery’s static analysis phase. It is a dynamic error (err:XC0104)
    if any error occurs during XQuery’s dynamic evaluation phase.
The output of this step may include PSVI annotations.
The static context of the XQuery processor is augmented in the following way:
- Statically known default collection type
- 
document()*
- Statically known namespaces:
- 
Unchanged from the implementation defaults. No namespace declarations in the XProc pipeline are automatically exposed in the static context. 
The dynamic context of the XQuery processor is augmented in the following way:
- Context item
- 
The first document that appears on the sourceport.
- Context position
- 
1
- Context size
- 
1
- Variable values
- 
Any parameters passed in the parametersoption augment any implementation-defined variable bindings known to the XQuery processor.
- Function implementations
- 
The function implementations provided by the XQuery processor. 
- Current dateTime
- 
The point in time returned as the current dateTime is implementation-defined. 
- Implicit timezone
- 
The implicit timezone is implementation-defined. 
- Available documents
- 
The set of available documents (those that may be retrieved with a URI) is implementation-dependent. 
- Available collections
- 
The set of available collections is implementation-dependent. 
- Default collection
- 
The sequence of documents provided on the sourceport.
The following pipeline applies XInclude processing and schema validation before using XQuery:
<p:declare-step xmlns:p="http://www.w3.org/ns/xproc"
                version="3.0">
<p:input port="source"/>
<p:output port="result"/>
<p:xinclude/>
<p:validate-with-xml-schema name="validate">
  <p:with-input port="schema" href="http://example.com/path/to/schema.xsd"/>
</p:validate-with-xml-schema>
<p:xquery>
   <p:with-input port="query" href="countp.xq"/>
</p:xquery>
</p:declare-step>Where countp.xq might contain:
<count>{count(.//p)}</count>No document properties are preserved.
The base-uri property of each document will
reflect the base URI specified by the query. If the query does not
establish a base URI, the document will not have one.
The p:xslt step invokes an XSLT stylesheet.
<p:declare-step type="p:xslt">
     <p:input port="source" content-types="any" sequence="true" primary="true"/>
     <p:input port="stylesheet" content-types="xml"/>
     <p:output port="result" primary="true" sequence="true" content-types="any"/>
     <p:output port="secondary" sequence="true" content-types="any"/>
     <p:option name="parameters" as="map(xs:QName,item()*)?"/>     
     <p:option name="static-parameters" as="map(xs:QName,item()*)?"/>
     <p:option name="global-context-item" as="item()?"/>           
     <p:option name="populate-default-collection" as="xs:boolean?" select="true()"/>
     <p:option name="initial-mode" as="xs:QName?"/>                
     <p:option name="template-name" as="xs:QName?"/>               
     <p:option name="output-base-uri" as="xs:anyURI?"/>            
     <p:option name="version" as="xs:string?"/>                    </p:declare-step>
If output-base-uri is relative, it is made absolute against the base URI of
    the element on which it is specified (p:with-option or p:xslt in the case
    of a syntactic shortcut value).
If the step specifies a version, then that version of XSLT
    must be used to process the transformation. It is a
      dynamic error (err:XC0038) if the specified xslt version is not available. If
    the step does not specify a version, the implementation may use any version it has available and
    may use any means to determine what version to use, including, but not limited to, examining the
    version of the stylesheet. It is implementation-defined which XSLT
    version(s) is/are supported.
The XSLT stylesheet provided on the stylesheet port is invoked.  It is a dynamic error (err:XC0093) if a static error occurs during the
    static analysis of the XSLT stylesheet. Any parameters passed in the
    parameters option are used to define top-level stylesheet parameters.
Parameters passed in the static-parameters option are passed as static
    parameters to the XSLT invocation. Whether static parameters are supported is
      implementation-defined and depends on the XSLT version (which must be
    3.0 or higher). If static parameters are not supported the option is ignored.
It is a dynamic error (err:XC0095) if an error occurred during
    the transformation.
    It is a dynamic error (err:XC0096) if the transformation is
      terminated by XSLT message termination.
    How XSLT message termination errors are reported to the XProc processor is
      implementation-dependent. Implementations
    should raise an error using the error code from the XSLT step (for example,
    the error-code specified on the xsl:message or
    Q{http://www.w3.org/2005/xqt-errors}XTTM9000 if no code is provided).
If XSLT 2.0 or XSLT 3.0 is used, the outputs of this step may include PSVI annotations.
The interpretation of the input and output ports as well as for the other options depends on the selected XSLT version.
The value of global-context-item is used as global context item for the
      stylesheet invocation. If no value is supplied, the following applies:
- 
        If there is a single document on the sourceport, this document will become the value of theglobal-context-itemoption.
- 
        If there are none or multiple documents on the sourceport, the global context item is absent.
The populate-default-collection option is used to control whether all
    the documents appearing on source port form the default collection for the XSLT
    transformation.
If no value is supplied for template-name option an “Apply-template
      invocation” is performed. The documents that appear on source are taken to be the
      initial match selection. The default collection is undefined. If a value is supplied for 
      the initial-mode option,
      this value is used as the initial-mode for the invocation. It is a
        dynamic error (err:XC0008) if the stylesheet does not support a given mode. 
      If no value is supplied, nothing is supplied to the invocation,
      so the default behaviour defined for XSLT 3.0 could be applied.
If a value is supplied for option template-name a “Call template
      invocation” is performed. The documents on port source are taken as the default
      collection in this case. Option initial-mode is ignored. It is a dynamic error (err:XC0056) if the stylesheet does not provide a given
        template.
Independent of the way the stylesheet is invoked, the principal result(s) will appear on
      output port result while secondary result(s) will appear on output port
      secondary. The order in which 
        result documents appear on the secondary port is
        implementation dependent. 
      Whether the raw results are delivered or a result tree is
      constructed, depends on the (explicit or implicit) setting for attribute
      build-tree of in the output-definition for the respective result. If a
      result tree is constructed, the result will be a text document if it is a single text node
      wrapped into a document node. Otherwise it will be either an XML document or an HTML document
      depending on the attribute method on the output-definition for the
      respective result. If no result tree is constructed, the stylesheet invocation may
      additionally deliver a sequence of atomic values, maps, or arrays. For each item in this
      sequence a JSON document will be constructed and appear on the steps output port.
Option output-base-uri sets the base output URI per XSLT 3.0
      specification. If a final result tree is constructed, this URI is used to resolve a relative
      URI reference. If no value is supplied for output-base-uri, the base URI of
      the first document in the source port's sequence is used. If no document is
      supplied on port source the base URI of the document on port stylesheet
      is used. It is a dynamic error (err:XC0121) if a document appearing
        on the secondary port has a base URI that is not both absolute and 
        valid according to [RFC 3986].
Note
If no result tree is constructed for one of secondary results, a sequence of documents
        sharing the same value for attribute href may appear on output port
        result.
If a sequence of documents is provided on the source port, the first document
      is used as the initial context node. The whole sequence is also the default collection. If no
      documents are provided on the source port, the initial context node is undefined
      and the default collection is empty. It is a dynamic
        error (err:XC0094) if any document supplied on the source port is not an XML document, an
        HTML documents, or a Text document if XSLT 2.0 is used.
The populate-default-collection option is used to control whether all
      the documents appearing on source port form the default collection for the XSLT
      transformation.
The value of option global-context-item is ignored if a stylesheet is
      invoked as per XSLT 2.0. The invocation of the transformation is controlled by the
      initial-mode and template-name options that set the
      initial mode and/or named template in the XSLT transformation where processing begins. It is a dynamic error (err:XC0007) if any key in
        parameters is associated to a value which is not an instance of the XQuery
        1.0 and XPath 2.0 Data Model, e.g. with a map, an array, or a function.
      It is a dynamic error (err:XC0008) if the specified initial mode
        cannot be applied to the specified stylesheet. 
      It is a dynamic error (err:XC0056) if the specified template 
        name cannot be applied to the specified stylesheet.
    
The primary result document of the transformation, if there is one, appears on the
      result port. At most one document can appear on the result port.
      All other result documents appear on the secondary port. The order in which 
        result documents appear on the secondary port is
        implementation dependent.
    
The output-base-uri option sets the context's output base URI per the
      XSLT 2.0 specification, otherwise the base URI of the result document is the base
      URI of the first document in the source port's sequence. If no document is
      supplied on port source the base URI of the document on port stylesheet
      is used. It is a dynamic error (err:XC0121) if a document appearing
        on the secondary port has a base URI that is not both absolute and 
        valid according to [RFC 3986].
The document provided for source is used the transformations source tree.
      It is a dynamic error (err:XC0039) if the source port does not
        contain exactly one XML document or one HTML document if XSLT 1.0 is used. The
      values supplied for options global-context-item,
      initial-mode, and template-name are ignored. If XSLT 1.0
      is used, an empty sequence of documents must appear on the
      secondary port. An XSLT 1.0 step should use the value of the
      output-base-uri as the base URI of its output, if the option is
      specified.
The key/value pairs supplied in parameters are used to set top-level
      parameters in the stylesheet. If the value is an atomic value or a node, its string value is
      supplied to the stylesheet. It is a dynamic error (err:XC0105) if an XSLT 1.0
      stylesheet is invoked and option parameters contains a value that is not an atomic value
      or a node.
    
Document properties
No document properties are
    preserved. The base-uri property of each
    document will reflect the base URI specified by the tranformation.
    If the transformation does not establish a base URI, the document
    will not have one.
Several of the steps in the standard step library can generate dynamic errors.
A [Definition: A dynamic error is one which occurs while a pipeline is being evaluated.] Examples of dynamic errors include references to URIs that cannot be resolved, steps which fail, and pipelines that exhaust the capacity of an implementation (such as memory or disk space).
If a step fails due to a dynamic error, failure propagates
upwards until either a p:try is encountered or the entire
pipeline fails. In other words, outside of a p:try, step
failure causes the entire pipeline to fail.
Dynamic errors raised by steps are divided into two categories: dynamic errors and step errors. The distinction is largely that “step errors” tend to be related to a particular step or small group of steps (e.g., validation error) whereas the “dynamic errors” apply to many more steps (e.g., URI not available). There is also precedent for some of the error codes dating back to XProc 1.0.
Dynamic Errors
- err:XD0011
- It is a dynamic error if the resource referenced by the href option does not exist, cannot be accessed or is not a file. 
- err:XD0023
- It is a dynamic error if a DTD validation is performed and either the document is not valid or no DTD is found. - See: Loading XML data 
- err:XD0043
- It is a dynamic error if the dtd-validate parameter is true and the processor does not support DTD validation. - See: Loading XML data 
- err:XD0049
- It is a dynamic error if the text value is not a well-formed XML document 
- err:XD0057
- It is a dynamic error if the text document does not conform to the JSON grammar, unless the parameter liberal is true and the processor chooses to accept the deviation. 
- err:XD0058
- It is a dynamic error if the parameter duplicates is reject and the text document contains a JSON object with duplicate keys. 
- err:XD0059
- It is a dynamic error if the parameter map contains an entry whose key is defined in the specification of fn:parse-json and whose value is not valid for that key, or if it contains an entry with the key fallback when the parameter escape with true() is also present. 
- err:XD0060
- It is a dynamic error if the text document can not be converted into the XPath data model 
- err:XD0062
- It is a dynamic error if the content-type is specified and the document-properties has a “content-type” that is not the same. - See: p:load 
- err:XD0064
- It is a dynamic error if the base URI is not both absolute and valid according to . - See: p:archive, p:archive-manifest, p:load, p:make-absolute-uris, p:set-properties, p:unarchive 
- err:XD0070
- It is a dynamic error if a value is assigned to the serialization document property that cannot be converted into map(xs:QName, item()*) according to the rules in section “QName handling” of . - See: p:set-properties 
- err:XD0078
- It is a dynamic error if the loaded document cannot be represented as an HTML document in the XPath data model. - See: Loading HTML data 
- err:XD0079
- It is a dynamic error if a supplied content-type is not a valid media type of the form “type/subtype+ext” or “type/subtype”. - See: Overriding content types, p:cast-content-type, p:http-request, p:http-request, p:load, p:text-join, p:uncompress 
Step Errors
- err:XC0001
- It is a dynamic error if the value of option override-content-type is not a text media type. - See: p:text-join 
- err:XC0003
- It is a dynamic error if a “username” or a “password” key is present without specifying a value for the “auth-method” key, if the requested auth-method isn't supported, or the authentication challenge contains an authentication method that isn't supported. - See: p:http-request 
- err:XC0007
- It is a dynamic error if any key in parameters is associated to a value which is not an instance of the XQuery 1.0 and XPath 2.0 Data Model, e.g. with a map, an array, or a function. 
- err:XC0008
- It is a dynamic error if the stylesheet does not support a given mode. - See: Invoking an XSLT 3.0 stylesheet, Invoking an XSLT 2.0 stylesheet 
- err:XC0009
- It is a dynamic error if the specified XQuery version is not available. - See: p:xquery 
- err:XC0013
- It is a dynamic error if the pattern matches a processing instruction and the new name has a non-null namespace. - See: p:rename 
- err:XC0014
- It is a dynamic error if the XML namespace (http://www.w3.org/XML/1998/namespace) or the XMLNS namespace (http://www.w3.org/2000/xmlns/) is the value of either the from option or the to option. - See: p:namespace-rename 
- err:XC0019
- It is a dynamic error if the documents are not equal according to the specified comparison method, and the value of the fail-if-not-equal option is true. - See: p:compare 
- err:XC0023
- It is a dynamic error if the selection pattern matches a node which is not an element. - See: p:add-attribute, p:delete, p:insert, p:label-elements, p:make-absolute-uris, p:rename, p:replace, p:set-attributes, p:unwrap, p:wrap 
- err:XC0024
- It is a dynamic error if the selection pattern matches a document node and the value of the position is “before” or “after”. - See: p:insert 
- err:XC0025
- It is a dynamic error if the selection pattern matches anything other than an element or a document node and the value of the position option is “first-child” or “last-child”. - See: p:insert 
- err:XC0029
- It is a dynamic error if an XInclude error occurs during processing. - See: p:xinclude 
- err:XC0030
- It is a dynamic error if the response body cannot be interpreted as requested (e.g. application/json to override application/xml content). - See: p:http-request 
- err:XC0036
- It is a dynamic error if the requested hash algorithm is not one that the processor understands or if the value or parameters are not appropriate for that algorithm. - See: p:hash 
- err:XC0037
- It is a dynamic error if the value provided is not a properly x-www-form-urlencoded value. - See: p:www-form-urldecode 
- err:XC0038
- It is a dynamic error if the specified xslt version is not available. - See: p:xslt 
- err:XC0039
- It is a dynamic error if the source port does not contain exactly one XML document or one HTML document if XSLT 1.0 is used. 
- err:XC0050
- It is a dynamic error if the URI scheme is not supported or the step cannot store to the specified location. - See: p:store 
- err:XC0056
- It is a dynamic error if the stylesheet does not provide a given template. - See: Invoking an XSLT 3.0 stylesheet, Invoking an XSLT 2.0 stylesheet 
- err:XC0058
- It is a dynamic error if the all and relative options are both true. - See: p:add-xml-base 
- err:XC0059
- It is a dynamic error if the QName value in the attribute-name option uses the prefix “xmlns” or any other prefix that resolves to the namespace name http://www.w3.org/2000/xmlns/. - See: p:add-attribute 
- err:XC0060
- It is a dynamic error if the processor does not support the specified version of the UUID algorithm. - See: p:uuid 
- err:XC0062
- It is a dynamic error if the match option matches a namespace node. - See: p:delete 
- err:XC0069
- It is a dynamic error if the properties map contains a key equal to the string “content-type”. - See: p:set-properties 
- err:XC0071
- It is a dynamic error if the p:cast-content-type step cannot perform the requested cast. - See: p:cast-content-type 
- err:XC0072
- It is a dynamic error if the c:data contains content is not a valid base64 string. 
- err:XC0073
- It is a dynamic error if the c:data element does not have a content-type attribute. 
- err:XC0074
- It is a dynamic error if the content-type is supplied and is not the same as the content-type specified on the c:data element. 
- err:XC0076
- It is a dynamic error if the comparison method specified in p:compare is not supported by the implementation. - See: p:compare 
- err:XC0077
- It is a dynamic error if the media types of the documents supplied are incompatible with the comparison method. - See: p:compare 
- err:XC0078
- It is a dynamic error if the value associated with the “fail-on-timeout” is associated with true() and a HTTP status code 408 is encountered. - See: p:http-request 
- err:XC0079
- It is a dynamic error if the map parameters contains an entry whose key is defined by the implementation and whose value is not valid for that key. - See: p:archive, p:archive-manifest, p:cast-content-type, p:compress, p:unarchive, p:uncompress 
- err:XC0080
- It is a dynamic error if the number of documents on the archive does not match the expected number of archive input documents for the given format and command. 
- err:XC0081
- It is a dynamic error if the format of the archive does not match the format as specified in the format option. - See: p:archive 
- err:XC0084
- It is a dynamic error if two or more documents appear on the p:archive step's source port that have the same base URI or if any document that appears on the source port has no base URI. - See: p:archive 
- err:XC0085
- It is a dynamic error if the format of the archive does not match the specified format, cannot be understood, determined and/or processed. 
- err:XC0092
- It is a dynamic error if as a consequence of changing or removing the namespace of an attribute the attribute's name is not unique on the respective element. - See: p:namespace-rename 
- err:XC0093
- It is a dynamic error if a static error occurs during the static analysis of the XSLT stylesheet. - See: p:xslt 
- err:XC0094
- It is a dynamic error if any document supplied on the source port is not an XML document, an HTML documents, or a Text document if XSLT 2.0 is used. 
- err:XC0095
- It is a dynamic error if an error occurred during the transformation. - See: p:xslt 
- err:XC0096
- It is a dynamic error if the transformation is terminated by XSLT message termination. - See: p:xslt 
- err:XC0098
- It is a dynamic error if a dynamic XPath error occurred while applying sort-key to a line. - See: p:text-sort 
- err:XC0099
- It is a dynamic error if the result of applying sort-key to a given line results in a sequence with more than one item. - See: p:text-sort 
- err:XC0100
- It is a dynamic error if the document on port manifest does not conform to the given schema. - See: p:archive 
- err:XC0101
- It is a dynamic error if a document appearing on port source cannot be represented in the XDM version associated with the chosen XQuery version, e.g. when a JSON document contains a map and XDM 3.0 is used. - See: p:xquery 
- err:XC0102
- It is a dynamic error if any key in option parameters is associated to a value that cannot be represented in the XDM version associated with the chosen XQuery version, e.g. with a map, an array, or a function when XDM 3.0 is used. - See: p:xquery 
- err:XC0103
- It is a dynamic error if any error occurs during XQuery’s static analysis phase. - See: p:xquery 
- err:XC0104
- It is a dynamic error if any error occurs during XQuery’s dynamic evaluation phase. - See: p:xquery 
- err:XC0105
- It is a dynamic error if an XSLT 1.0 stylesheet is invoked and option parameters contains a value that is not an atomic value or a node. 
- err:XC0106
- It is a dynamic error if duplicate keys are encountered and option duplicates has value “reject”. - See: p:json-merge 
- err:XC0107
- It is a dynamic error if a document of a not supported document type appears on port source of p:json-merge. - See: p:json-merge 
- err:XC0108
- It is a dynamic error if any prefix is not in-scope at the point where the p:namespace-delete occurs. - See: p:namespace-delete 
- err:XC0109
- It is a dynamic error if a namespace is to be removed from an attribute and the element already has an attribute with the resulting name. - See: p:namespace-delete 
- err:XC0110
- It is a dynamic error if the evaluation of the XPath expression in option key for a given item returns either a sequence, an array, a map, or a function. - See: p:json-merge 
- err:XC0111
- It is a dynamic error if a document of an unsupported document type appears on port source of p:json-join. - See: p:json-join 
- err:XC0112
- It is a dynamic error if more than one document appears on the port manifest. - See: p:archive 
- err:XC0118
- It is a dynamic error if an archive manifest is invalid according to the specification. - See: The archive manifest 
- err:XC0119
- It is a dynamic error if flatten is neither “unbounded”, nor a string that may be cast to a non-negative integer. - See: p:json-join 
- err:XC0120
- It is a dynamic error if the relative-to option is not present and the document on the source port does not have a base URI. 
- err:XC0121
- It is a dynamic error if a document appearing on the secondary port has a base URI that is not both absolute and valid according to . - See: Invoking an XSLT 3.0 stylesheet, Invoking an XSLT 2.0 stylesheet 
- err:XC0122
- It is a dynamic error if the given method is not supported. - See: p:http-request 
- err:XC0123
- It is a dynamic error if any key in the “auth” map is associated with a value that is not an instance of the required type. - See: p:http-request 
- err:XC0124
- It is a dynamic error if any key in the “parameters” map is associated with a value that is not an instance of the required type. - See: p:http-request 
- err:XC0125
- It is a dynamic error if the key “accept-multipart” as the value false() and a multipart response is detected. - See: p:http-request 
- err:XC0126
- It is a dynamic error if the XPath expression in assert evaluates to false. - See: p:http-request 
- err:XC0127
- It is a dynamic error if the headers map contains two keys that are the same when compared in a case-insensitive manner. - See: p:http-request 
- err:XC0128
- It is a dynamic error if the URI’s scheme is unknown or not supported. - See: p:http-request 
- err:XC0129
- It is a dynamic error if the requested HTTP version is not supported. - See: p:http-request 
- err:XC0131
- It is a dynamic error if the processor cannot support the requested encoding. - See: p:http-request 
- err:XC0132
- It is a dynamic error if the override content encoding cannot be supported. - See: p:http-request 
- err:XC0133
- It is a dynamic error if more than one document appears on the source port and a content-type header is present and the content type specified is not a multipart content type. 
- err:XC0146
- It is a dynamic error if the specified value for the override-content-types option is not an array of arrays, where the inner arrays have exactly two members of type xs:string. 
- err:XC0147
- It is a dynamic error if the specified value is not a valid XPath regular expression. 
- err:XC0150
- It is a dynamic error if evaluating the XPath expression in option test on a context document results in an error. - See: p:split-sequence 
- err:XC0201
- It is a dynamic error if the p:uncompress step cannot perform the requested content-type cast. - See: p:uncompress 
- err:XC0202
- It is a dynamic error if the compression format cannot be understood, determined and/or processed. - See: p:compress, p:uncompress 
A. Conformance
Conformant processors must implement all of the features described in this specification except those that are explicitly identified as optional.
Some aspects of processor behavior are not completely specified; those features are either implementation-dependent or implementation-defined.
[Definition: An implementation-dependent feature is one where the implementation has discretion in how it is performed. Implementations are not required to document or explain how implementation-dependent features are performed.]
[Definition: An implementation-defined feature is one where the implementation has discretion in how it is performed. Conformant implementations must document how implementation-defined features are performed.]
The following features are implementation-defined:
- The list of formats supported by the p:archive step is implementation-defined. See Section 2.3, “p:archive”.
- The list of archive formats that can be modified by p:archive is implementation-defined. See Section 2.3, “p:archive”.
- The semantics of any additional attributes, elements and their values are implementation-defined. See Section 2.3, “p:archive”.
- It is implementation-defined what other formats are supported. See Section 2.3, “p:archive”.
- The semantics of the keys and the allowed values for these keys are implementation-defined. See Section 2.3, “p:archive”.
- It is implementation-defined what other formats are supported. See Section 2.3, “p:archive”.
- It is implementation-defined how the step determines the archive's format. See Section 2.3, “p:archive”.
- The c:archive root element may contain additional implementation-defined attributes. See Section 2.3.1, “The archive manifest”.
- The default compression method is implementation-defined. See Section 2.3.1, “The archive manifest”.
- It is implementation-defined what other compression methods are supported. See Section 2.3.1, “The archive manifest”.
- The default compression method is implementation-defined. See Section 2.3.1, “The archive manifest”.
- It is implementation-defined what compression levels are supported. See Section 2.3.1, “The archive manifest”.
- The c:entry elements may contain additional implementation-defined attributes. See Section 2.3.1, “The archive manifest”.
- The p:archive step may support additional, implementation-defined commands for ZIP files. See Section 2.3.2, “Handling of ZIP archives”.
- The actual parameter names supported by p:archive for a particular format are implementation-defined. See Section 2.3.2, “Handling of ZIP archives”.
- It is implementation-defined what other formats are supported. See Section 2.4, “p:archive-manifest”.
- It is implementation-defined how the step determines the archive's format. See Section 2.4, “p:archive-manifest”.
- The semantics of the keys and the allowed values for these keys are implementation-defined. See Section 2.4, “p:archive-manifest”.
- Additional information provided for entries in p:archive-manifest is implementation-defined. See Section 2.4, “p:archive-manifest”.
- The semantics of the keys and the allowed values for these keys are implementation-defined. See Section 2.5, “p:cast-content-type”.
- The precise nature of the conversion from XML to JSON is implementation-defined. See Section 2.5.1, “Casting from an XML media type”.
- Casting from an XML media type to any other media type when the input document is not a c:data document is implementation-defined. See Section 2.5.1, “Casting from an XML media type”.
- Casting from an HTML media type to a JSON media type is implementation-defined. See Section 2.5.2, “Casting from an HTML media type”.
- Casting from an HTML media type to any other media type is implementation-defined. See Section 2.5.2, “Casting from an HTML media type”.
- It is implementation-defined whether other result formats are supported. See Section 2.5.3, “Casting from a JSON media type”.
- Casting from a JSON media type to an HTML media type is implementation-defined. See Section 2.5.3, “Casting from a JSON media type”.
- Casting from a JSON media type to any other media type is implementation-defined. See Section 2.5.3, “Casting from a JSON media type”.
- The precise way in which text documents are parsed into the XPath data model is implementation-defined. See Section 2.5.4, “Casting from a text media type”.
- Casting from a text media type to any other media type is implementation-defined. See Section 2.5.4, “Casting from a text media type”.
- Casting from any other media type to a HTML media type, a JSON media type or a text document is implementation-defined. See Section 2.5.5, “Casting from any other media type”.
- Casting from any other media type to any other media type is implementation-defined. See Section 2.5.5, “Casting from any other media type”.
- Implementations of p:compare must support the deep-equal method; other supported methods are implementation-defined. See Section 2.6, “p:compare”.
- If fail-if-not-equal is false, and the documents differ, an implementation-defined summary of the differences between the two documents may appear on the differences port. See Section 2.6, “p:compare”.
- It is implementation-defined what other formats are supported. See Section 2.7, “p:compress”.
- The semantics of the keys and the allowed values for these keys are implementation-defined. See Section 2.7, “p:compress”.
- It is implementation-defined what other algorithms are supported. See Section 2.12, “p:hash”.
- It is implementation-defined how a multipart boundary is constructed. See Section 2.13.1, “Construction of a multipart request”.
- In the absence of an explicit type, the content type is implementation-defined See Section 2.19, “p:load”.
- Additional XML parameters are implementation-defined. See Section 2.19.1, “Loading XML data”.
- Text parameters are implementation-defined. See Section 2.19.2, “Loading text data”.
- Additional JSON parameters are implementation-defined. See Section 2.19.3, “Loading JSON data”.
- The precise way in which HTML documents are parsed into the XPath data model is implementation-defined. See Section 2.19.4, “Loading HTML data”.
- HTML parameters are implementation-defined. See Section 2.19.4, “Loading HTML data”.
- How a processor interprets other media types is implementation-defined. See Section 2.19.5, “Loading binary data”.
- Parameters for other media types are implementation-defined. See Section 2.19.5, “Loading binary data”.
- Support for other collations is implementation-defined. See Section 2.36, “p:text-sort”.
- It is implementation-defined what other formats are supported. See Section 2.38, “p:unarchive”.
- It is implementation-defined how the step determines the archive's format. See Section 2.38, “p:unarchive”.
- The semantics of the keys and the allowed values for these keys are implementation-defined. See Section 2.38, “p:unarchive”.
- It is implementation-defined what other formats are supported. See Section 2.39, “p:uncompress”.
- It is implementation-defined how the step determines the compression format. See Section 2.39, “p:uncompress”.
- The semantics of the keys and the allowed values for these keys are implementation-defined. See Section 2.39, “p:uncompress”.
- If the version is not specified, the version of UUID computed is implementation-defined. See Section 2.41, “p:uuid”.
- Support for other versions of UUID, and the mechanism by which the necessary inputs are made available for computing other versions, is implementation-defined. See Section 2.41, “p:uuid”.
- Support for XQueryX is implementation-defined. See Section 2.47, “p:xquery”.
- The point in time returned as the current dateTime is implementation-defined. See Section 2.47, “p:xquery”.
- The implicit timezone is implementation-defined. See Section 2.47, “p:xquery”.
- It is implementation-defined which XSLT version(s) is/are supported. See Section 2.48, “p:xslt”.
- Whether static parameters are supported is implementation-defined and depends on the XSLT version (which must be 3.0 or higher). See Section 2.48, “p:xslt”.
The following features are implementation-dependent:
- If the IRI reference specified by the base-uri option on p:make-absolute-uris is absent and the input document has no base URI, the results are implementation-dependent. See Section 2.20, “p:make-absolute-uris”.
- The set of available documents (those that may be retrieved with a URI) is implementation-dependent. See Section 2.47, “p:xquery”.
- The set of available collections is implementation-dependent. See Section 2.47, “p:xquery”.
- How XSLT message termination errors are reported to the XProc processor is implementation-dependent. See Section 2.48, “p:xslt”.
B. References
[XProc 3.0] XProc 3.0: An XML Pipeline Language. Norman Walsh, Achim Berndzen, Gerrit Imsieke and Erik Siegel, editors.
[W3C XML Schema: Part 2] XML Schema Part 2: Datatypes Second Edition. Paul V. Biron and Ashok Malhotra, editors. World Wide Web Consortium, 28 October 2004.
[XPath 3.1] XML Path Language (XPath) 3.1. Jonathan Robie, Michael Dyck, Josh Spiegel, editors. W3C Recommendation. 21 March 2017.
[XPath and XQuery Functions and Operators 3.1] XPath and XQuery Functions and Operators 3.1. Michael Kay, editor. W3C Recommendation. 21 March 2017
[XSLT 3.0] XSL Transformations (XSLT) Version 3.0. Michael Kay, editor. W3C Recommendation. 8 June 2017.
[XInclude] XML Inclusions (XInclude) Version 1.0 (Second Edition). Jonathan Marsh, David Orchard, and Daniel Veillard, editors. W3C Recommendation. 15 November 2006.
[RFC 1321] RFC 1321: The MD5 Message-Digest Algorithm. R. Rivest. Network Working Group, IETF, April 1992.
[RFC 1521] RFC 1521: MIME (Multipurpose Internet Mail Extensions) Part One: Mechanisms for Specifying and Describing the Format of Internet Message Bodies. N. Borenstein. Network Working Group, IETF, September 1993.
[RFC 2046] RFC 2046: Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types. N. Freed, N. Borenstein, editors. Internet Engineering Task Force. November, 1996.
[RFC 2119] Key words for use in RFCs to Indicate Requirement Levels. S. Bradner. Network Working Group, IETF, Mar 1997.
[RFC 2617] RFC 2617: HTTP Authentication: Basic and Digest Access Authentication. J. Franks, P. Hallam-Baker, J. Hostetler, S. Lawrence, P. Leach, A. Luotonen, L. Stewart. June, 1999 .
[RFC 3986] RFC 3986: Uniform Resource Identifier (URI): General Syntax. T. Berners-Lee, R. Fielding, and L. Masinter, editors. Internet Engineering Task Force. January, 2005.
[CRC32] “32-Bit Cyclic Redundancy Codes for Internet Applications”, The International Conference on Dependable Systems and Networks: 459. 10.1109/DSN.2002.1028931. P. Koopman. June 2002.
C. Glossary
- dynamic error
- A dynamic error is one which occurs while a pipeline is being evaluated. 
- implementation-defined
- An implementation-defined feature is one where the implementation has discretion in how it is performed. Conformant implementations must document how implementation-defined features are performed. 
- implementation-dependent
- An implementation-dependent feature is one where the implementation has discretion in how it is performed. Implementations are not required to document or explain how implementation-dependent features are performed. 
D. Ancillary files
This specification includes by reference a number of ancillary files.
- steps.xpl
- 
An XProc step library for the declared steps. 
E. Credits
This document is derived from XProc: An XML Pipeline Language published by the W3C. It was developed by the XML Processing Model Working Group and edited by Norman Walsh, Alex Miłowski, and Henry Thompson.
The editors of this specification extend their gratitude to everyone who contributed to this document and all of the versions that came before it.
F. Change Log
This appendix catalogs non-editorial changes made after the February 2020 “last call” draft:
- 
    For p:cast-content-typethe expected result type for casting ac:param-setdocument to “application/json” was specified asmap(xs:QName, xs:string). (2020-03-15)
- 
    In p:http-request, instead of using all document properties (with a few explicit exceptions) as headers, only document properties in thehttp://www.w3.org/ns/xproc-httpnamespace will be used. (2020-03-18)
- 
     Section 2.3.1, “The archive manifest”: An attribute c:entry/@content-typewas added to the archive manifest, to be filled by thep:archive-manifeststep. (2020-03-20)
- 
     A static-parameterswas added top:xslt. (2020-03-23)
- 
     The override-content-typesoption was added top:archive-manifestandp:unarchive. (2020-03-30)
- 
        Clarified the regular expression matching for p:text-replaceandp:unarchive. Added an error code for invalid regular expressions. (2020-04-02)
- 
     Replaced errors XC0070 and XC0130 with XD0079. (2020-04-09) 
- 
     Changed signature of p:split-sequenceso that any document can appear one port source. (2020-05-22)
- 
     Change the behavior of the global-context-itemoption ofp:xslt. (2020-06-10)
- 
     Clarified which steps may produce PSVI annotations. (2020-06-09) 
- 
     Clarified the behaviour in p:archive: A missing resource referenced by c:archive/c:entry/@href is only an error for command = 'create'. (2020-06-11)
- 
     Option populate-default-collectionis added to the signature ofp:xslt. (2020-06-20)
- 
     Clarified how the default content-typeheader ofp:http-requestis constructed if a single document appears onsourceport. (2020-06-20)
- 
     Added error (XD0079) to p:http-requestandp:loadfor invalid content-types. (2020-06-23)
- 
     Changed signature of the resultport ofp:loadtosequence="false"and adapted the prose accordingly. (2020-06-24)