Core functions

xxf:document-id()

xxf:document-id() as xs:string`

Each time an XForms document is created, typically when a user requests a page, it is assigned a unique id.

This function returns the current XForms document (or page)'s unique id.

xxf:evaluate-avt()

xxf:evaluate-avt(
    $avt-expression as xs:string
) as item()*

This function is similar to saxon:evaluate() or xxf:evaluate(), but instead of evaluating an XPath expression, it evaluates a string representing an attribute value template.

<xf:output
    value="
        xxf:evaluate-avt(
            '/xforms-sandbox/service/zip-zips?state-abbreviation={state}&amp;city={city}'
        )"/>

xxf:format-message()

xxf:format-message($template as xs:string, $parameters as item()*) as xs:string

The xxf:format-message() function allows you to format a localized message based on a template and parameters.

• the first parameter is a template string following the syntax of the Java MessageFormat class

• the second parameter is a sequence of parameters that can be referenced from the template string

The following types are supported:

• string (the default)

• number (including currency and percent)

• date

• time

The function uses the current language as would be obtained by the xxf:lang() function to determine a locale.

Example with number, date, time, and string:

<xf:output
    value="
        xxf:format-message(
            'At {2,time,short} on {2,date,long}, we detected {1,number,integer} spaceships on the planet {0}.',
            (
                'Mars',
                3,
                xs:dateTime('2010-07-23T19:25:13-07:00')
            )
        )"/>

This produces the following output with an en-US locale:

At 7:25 PM on July 23, 2010, we detected 3 spaceships on the planet Mars.

Example including a choice:

<xf:output
    value="
        xxf:format-message(
            'There {0,choice,0#are no files|1#is one file|1&lt;are {0,number,integer} files}.',
            xs:integer(.)
        )"/>

This produces the following outputs, depending on the value provided:

There are no files.
There is one file.
There are 1,273 files.

NOTE: It is important to pass dates and times as typed values. Use xs:dateTime(), xs:date(), or xs:time() if needed to convert from a string.

xxf:lang()

xxf:lang() as xs:string?

The xxf:lang() function returns the current language as specified with the xml:lang attribute.

The xml:lang value to use is determined this way:

• if the element containing the xxf:lang() function has an xml:lang attribute, that attribute is used

• otherwise, the first ancestor element of the element containing the xxf:lang() function that has an xml:lang attribute is used

xml:lang is supported in the following locations:

• for a static xml:lang value

  • on any XForms element

  • on the top-level <xh:html> element

• for a dynamic xml:lang value (using an AVT)

  • only on the top-level <xh:html> element

NOTE: xml:lang attributes on HTML elements other than the top-level <xh:html> are ignored for the purpose of the xxf:lang() function.

NOTE: Format of the locale is currently restricted to the form "en" or "en-GB". Support for BCP 47 would be desirable.

Example of static values:

<xf:group xml:lang="it">
    <!-- This output produces the value "it" -->
    <xf:output value="xxf:lang()"/>
    <!-- This output produces the value "zh" -->
    <xf:output value="xxf:lang()" xml:lang="zh"/>
</xf:group>

Example with an AVT:

<xh:html xml:lang="{instance()}">
    <xh:head>
        <xf:model id="model">
            <xf:instance id="instance">
                <lang>it</lang>
            </xf:instance>
        </xf:model>
    </xh:head>
    <xh:body>
        <xf:group>
            <!-- This output produces "it" based on the top-level AVT, which
                 contains the value stored in the instance -->
            <xf:output value="xxf:lang()"/>
            <!-- This output produces "zh" -->
            <xf:output value="xxf:lang()" xml:lang="zh"/>
        </xf:group>
    </xh:body>
</xh:html>

When calling the xxf:lang() function from an XBL component:

• xml:lang is first searched as described above

• if no xml:lang value is found in the XBL component, then the xml:lang value of the XBL bound element is searched

Example:

<xbl:xbl>
    <xbl:binding id="fr-foo" element="fr|foo">
        <xbl:template>
            <xf:group>
                <!-- The xml:lang value of the bound element is used -->
                <xf:output value="xxf:lang()"/>
                <!-- The xml:lang value is "zh" -->
                <xf:output value="xxf:lang()" xml:lang="zh"/>
            </xf:group>
        </xbl:template>
    </xbl:binding>
</xbl:xbl>

xxf:property()

xxf:property($property-name as xs:string) as xs:anyAtomicType?

The xxf:property() function retrieves the value of a property defined in properties-local.xml.

This function returns the following:

• empty sequence if the property is not found

• xs:string, xs:integer, xs:boolean or xs:anyURI depending on the actual type of the property

<xf:setvalue ref="my-property" value="xxf:property('my.property.name')"/>

xxf:r()

The purpose of this function is to automatically resolve resources by name given the current language and an XForms instance containing localized resources.

xxf:r($resource-name as xs:string) as xs:string
xxf:r($resource-name as xs:string, $instance-name as xs:string) as xs:string

• $resource-name: resource path of the form foo.bar.baz. The path is relative to the resource element corresponding to the current language in the resources instance.

• $instance-name: name of the resources instance. If omitted, search orbeon-resources and then fr-form-resources.

The function:

• determines the current language based on xml:langattribute in scope where the function is in used

• resolves the closest relevant resources instance

  • specified instance name if present

  • orbeon-resources or fr-form-resources (for Form Runner compatibility) if absent

• uses the resource name specified to find a resource located in the resources instance, relative to the resource element with the matching language

Example:

<xf:instance id="orbeon-resources" xxf:readonly="true">
    <resources>
        <resource xml:lang="en"><buttons><download>Download</download></buttons></resource>
        <resource xml:lang="fr"><buttons><download>Télécharger</download></buttons></resource>
    </resources>
</xf:instance>

<xf:label value="xxf:r('buttons.download')"/>

xxf:rewrite-resource-uri()

xxf:rewrite-resource-uri($uri as xs:string) as xs:string

Rewrite a URI as an Orbeon Forms resource URI.