XML functions

xf:attribute() / xxf:attribute()

NOTE: This function is also allowed in the XForms namespace, as it is being standardized in XForms 2.0. Prior to this date, it must be in the Orbeon xxf extension namespace.

xf:attribute(
    $qname as xs:anyAtomicType
) as attribute()

xf:attribute(
    $qname as xs:anyAtomicType,
    $value as xs:anyAtomicType?
) as attribute()

The xf:attribute() function returns a new XML attribute with the qualified name provided as first argument. If the qualified name is not of type xs:QName, its string value is used. If it has a prefix, it is resolved using in-scope namespaces. The second argument is an optional value for the attribute. It defaults to the empty string.

<!-- Add an attribute called "id" with a value of "first-name" to element "section" -->
<xf:insert
    context="section"
    origin="xf:attribute('id', 'first-name')"/>

The first argument can be of type xs:QName:

<!-- Add an attribute called "id" with a value of "foo:bar" to element "section"
     and resolve the namespaces on element $element -->
<xf:insert
    context="section"
    origin="xf:attribute(resolve-QName('foo:bar', $element), 'first-name')"/>

xxf:call-xpl()

xxf:call-xpl(
    $xplURL        as xs:string,
    $inputNames    as xs:string*,
    $inputElements as element()*,
    $outputNames   as xs:string+
) as document-node()*

This function lets you call an XPL pipeline.

• $xplURL is the URL of the pipeline. It must be an absolute URL.

• $inputNames is a sequence of strings, each one representing the name of an input of the pipeline that you want to connect.

• $inputElements is a sequence of elements to be used as input for the pipeline. The $inputNames and $inputElements sequences must have the same length. For each element in $inputElements, a document is created and connected to an input of the pipeline. Elements are matched to input name by position, for instance the element at position 3 of $inputElements is connected to the input with the name specified at position 3 in $inputNames.

• $outputNames is a sequence of output names to read.

The function returns a sequence of document nodes corresponding the output of the pipeline. The returned sequence will have the same length as $outputNames and will correspond to the pipeline output with the name specified on $outputNames based on position.

The example below shows a call to the xxf:call-xpl function, calling a pipeline with two inputs and one output:

xxf:call-xpl(
    'oxf:/examples/sandbox/xpath/run-xpath.xpl',
    (
        'input',
        'xpath'
    ),
    (
        instance('instance')/input,
        instance('instance')/xpath
    ),
    'html'
)

xxf:classes()

xxf:classes() as xs:boolean
xxf:classes($el as node()) as xs:string*

Returns for the context element or the given element if provided, all the classes on the class attribute.

xxf:create-document()

xxf:create-document() as document-node()

The xxf:create-document() creates a new empty XML document. You can then insert new data into that document with the xf:insert action.

<xf:var name="new" value="xxf:create-document()"/>
<xf:insert context="$new" origin="instance('my-data')"/>

xf:element() / xxf:element()

NOTE: This function is also allowed in the XForms namespace, as it is being standardized in XForms 2.0. Prior to this date, it must be in the Orbeon xxf extension namespace.

xf:element(
    $element-name as xs:anyAtomicType
) as element()

xf:element(
    $element-name as xs:anyAtomicType,
    $content      as item()*
) as element()

The xf:element() function returns a new XML element with the qualified name provided. If the qualified name is not of type xs:QName, its string value is used. If it has a prefix, it is resolved using in-scope namespaces.

<!-- Insert an element called "value" as a child of element "section" -->
<xf:insert
    context="section"
    origin="xf:element('value')">

The second, optional argument can take a sequence of items specifying attributes and content for the new element:

<!-- Insert an element called "value" as a child of element "section",
     with an attribute and text content -->
<xf:insert
    context="section"
    origin="xf:element('value', (xf:attribute('id', 'my-value'), 'John'))"/>

The first argument can be of type xs:QName:

<!-- Insert an element called "foo:bar" as a child of element "section"
     and resolve the namespaces on element $element -->
<xf:insert
    context="section"
    origin="xf:element(resolve-QName('foo:bar', $element))"/>

xxf:evaluate()

xxf:evaluate(
    $xpath as xs:string
) as item()*

The xxf:evaluate() function allows you to evaluate XPath expressions dynamically. For example:

<xf:input ref="xxf:evaluate(concat('instance(''my-instance'')/document', my-xpath))">
    <xf:label>...</xf:label>
</xf:input>

xxf:extract-document()

xxf:extract-document(
  $element as element()
) as document-node()

xxf:extract-document(
  $element               as element(),
  $excludeResultPrefixes as xs:boolean
) as document-node()

xxf:extract-document(
  $element               as element(),
  $excludeResultPrefixes as xs:boolean,
  $readonly as xs:boolean
) as document-node()

The xxf:extract-document() function extracts a new XML document from a document fragment under an enclosing element. For example with the following instance:

<xf:instance id="my-instance">
    <library>
        <book>
            <title>Jacques le fataliste et son maître</title>
            <author>Denis Diderot</author>
        </book>
    </library>
</xf:instance>

The expression:

xxf:extract-document(instance('my-instance')/book, '', false())

returns a new XML document rooted at the <book> element:

<book>
    <title>Jacques le fataliste et son maître</title>
    <author>Denis Diderot</author>
</book>

• $excludeResultPrefixes: optional parameter; contains a list of space-separated namespace prefixes to exclude. Defaults to the empty string.

• $readonly: optional parameter; when set to true(), return a readonly instance. Defaults to false().

xxf:form-urlencode()

xxf:form-urlencode($document as node()) as xs:string

Performs application/x-www-form-urlencoded encoding on an XML document.

xxf:has-class()

xxf:has-class($class-name as xs:string) as xs:boolean
xxf:has-class($class-name as xs:string, $el as node()) as xs:boolean

Returns whether the context element, or the given element, has a class attribute containing the specified class name.

xxf:mutable-document()

xxf:mutable-document(
    $node as node()
) as document-node()

The xxf:mutable-document() function takes a document as input and returns a mutable document, i.e. a document on which you can for example use xf:setvalue.

<xf:action ev:event="xforms-submit-serialize">
  <!-- Get initial document to submit -->
  <xf:var
    name="request-document"
    value="xxf:mutable-document(saxon:parse(/my/request))"/>
  <!-- Set value -->
  <xf:setvalue
    ref="$request-document/my/first-name">Joe</xf:setvalue>
  <!-- Serialize request document -->
  <xf:setvalue
    ref="event('submission-body')"
    value="saxon:serialize($request-document, instance('my-output-instance'))"/>
</xf:action>

Note that by compatibility with the XSLT document() and XPath 2.0 doc() functions, and unlike the instance() function, xxf:mutable-document() returns a document node, not a document element.

xxf:serialize()

xxf:serialize(
    $item as node(),
    $format as xs:string?
) as xs:string

The xxf:serialize() function allows you to serialize an XML node to XML, HTML, XHTML or text. For example:

<xf:bind ref="my-html" calculate="xxf:serialize(instance('my-instance'), 'html')"="">

xxf:sort()

xxf:sort(
    $sequence   as item()*,
    $sort-key   as item(),
    $datatype   as xs:string?,
    $order      as xs:string?,
    $case-order as xs:string?
) as item()*

Note that the second argument differs from the exf:sort() function: it does not take a plain string but a literal expression, for example:

<xf:itemset
  ref="
    xxf:sort(
        instance('samples-instance')/file,
        @name,
        'text',
        'ascending'
    )">
  ...
</xf:itemset>