XSLT Mediator¶
The XSLT Mediator applies a specified XSLT transformation to a selected element of the current message payload. In addition, you can:
- Specify properties already included in the mediation flow to be added to the XSLT script as XSLT parameters.
- Specify features to be enabled/disabled in the XSLT transformation.
- Import external XSLT scripts to the main XSLT script of the XSLT mediator by adding them as resources.
Info
The XSLT mediator is a content aware mediator.
Syntax¶
<xslt key="string" [source="xpath"]>
<property name="string" (value="literal" | expression="xpath")/>*
<feature name="string" value="true| false" />*
<resource location="string" key="string"/>*
</xslt>
Configuration¶
The parameters available for configuring the XSLT mediator are as follows.
Parameter Name | Description |
---|---|
Key Type | You can select one of the following options.
|
Key | This specifies the registry key to refer the XSLT to. This supports static and dynamic keys. |
Source | This determines the element to which the given XSLT transformation should be applied via an XPath expression. If the source element is not specified, the XSLT transformation is applied to the first child of the SOAP body. Tip You can click NameSpaces to add namespaces if you are providing an expression. Then the Namespace Editor panel would appear where you can provide any number of namespace prefixes and URLs used in the XPath expression. |
Properties of the XSLT mediator | This section is used to inject properties set in the mediation flow to the XSLT script as XSLT parameters. These are referred from the XSLT in transformation using the Parameters relating to the properties are as follows.
For example, define the |
Features of the XSLT mediator | This section is used to specify features to be enabled/disabled in the XSLT transformation. For example, adding the http://ws.apache.org/ns/synapse/transform/feature/dom feature turns on DOM-based transformations instead of serializing elements into byte streams and/or temporary files. This approach can improve performance but might not work for all transformations. Parameters relating to the features are as follows.
|
Resources of the XSLT mediator | This section is used to import external XSLT scripts to the main XSLT scripts defined in the XSLT mediator. The XSLT scripts to be imported are first added as resources in the registry. Parameters relating to the resources are as follows.
|
Example 1 - Applying an XSLT transformation to a element selected based on an XPath expression¶
In this example, the XSLT can be picked by the key
transform/example.xslt
and the XSLT would be applied
to a part of the message that is specified as an XPath expression. In
this case, it is applied to s11:Body/child
the
message.
<xslt xmlns="http://ws.apache.org/ns/synapse" key="transform/example.xslt" source="s11:Body/child" />
Example 2 - Adding properties as XSLT parameters¶
In this example, a property named PARAM_NAME
is added
to the XSLT script as an XSLT parameter. A XPath expression is used to
assign this property the value of the ORDER_ID
property in the default scope.
<xslt key="keyToXSLTFile">
<property expression="$ctx:ORDER_ID" name="PARAM_NAME">
</property></xslt>
The XSLT script with the PARAM_NAME
property added
would look as follows.
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:param name="PARAM_NAME"></xsl:param>
<xsl:template match="/">
<orders xmlns="http://services.samples">
<xsl:attribute name="id">
<xsl:value-of select="$PARAM_NAME">
</xsl:value-of></xsl:attribute>
</orders>
</xsl:template>
</xsl:stylesheet>
Example 3 - Adding XSLT imports as resources¶
In this example, two XSLT files saved in the registry under
conf:/
as resources are imported to the main XSLT
script of the XSLT mediator.
xslt1.xslt
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:template match="//people/person" name="FILL_PPL">
<client>
<firstname>
<xsl:value-of select="firstname">
</xsl:value-of></firstname>
<lastname>
<xsl:value-of select="lastname">
</xsl:value-of></lastname>
<age>
<xsl:value-of select="age">
</xsl:value-of></age>
<country>
<xsl:value-of select="country">
</xsl:value-of></country>
</client>
</xsl:template>
</xsl:stylesheet>
xslt2.xslt
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:import href="xslt1.xslt" />
<xsl:template match="/">
<clients>
<xsl:for-each select="//people/person">
<xsl:call-template name="FILL_PPL"></xsl:call-template>
</xsl:for-each>
</clients>
</xsl:template>
</xsl:stylesheet>
\<xsl:include href="xslt1.xslt"> element indicates that the
xslt1.xslt
is included in
xslt2.xslt
.
These two files can be imported to the script of the XSLT mediator as follows.
<xslt key="conf:/xslt2.xslt">
<resource key="conf:/xslt1.xslt" location="xslt1.xslt">
</resource></xslt>
The following SOAP request can be used to test the above configuration of the XSLT mediator included in a proxy configuration.
<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/">
<soapenv:Header>
<soapenv:Body>
<people>
<person>
<firstname>Isuru</firstname>
<lastname>Udana</lastname>
<gender>Male</gender>
<age>26</age>
<country>SriLanka</country>
</person>
<person>
<firstname>Ishan</firstname>
<lastname>Jayawardena</lastname>
<gender>Male</gender>
<age>26</age>
<country>SriLanka</country>
</person>
</people>
</soapenv:Body>
</soapenv:Header></soapenv:Envelope>
Example 4 - Adding CDATA to be displayed in the output¶
Follow the steps below to add CDATA to display them in the output without processing them via the XSLT transformation.
- Create a file named
XMLInputFactory.properties
inside the<EI_HOME>
directory, and include the following property in it:javax.xml.stream.isCoalescing=
false
- Add the
<xsl:output method="xml" omit-xml-declaration="yes" indent="yes"/>
attribute to the XSL stylesheet. -
In the XSL stylesheet, wrap the encoded CDATA within the
<xsl:text>
elements with thedisable-output-escaping="yes"
parameter as shown below.<xsl:text disable-output-escaping="yes"><![CDATA[</xsl:text> <xsl:copy-of select="*"/> <xsl:text disable-output-escaping="yes">]]></xsl:text>
The following is an example of a XSL stylesheet, which includes CDATA to be displayed in the output.
<xsl:stylesheet version="2.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output method="xml" omit-xml-declaration="yes" indent="yes"/>
<xsl:template match="/">
<root>
<xsl:copy>
<xsl:text disable-output-escaping="yes"><![CDATA[</xsl:text>
<xsl:copy-of select="*"/>
<xsl:text disable-output-escaping="yes">]]></xsl:text>
</xsl:copy>
</root>
</xsl:template>
</xsl:stylesheet>
You can use the following Synapse configuration to process the above XSL
stylesheet via a XSLT mediator. In the above configuration, the XSL
stylesheet is defined as a local entry named XSLTTest
, and it is referred in the XSLT mediator configuration via the
key
attribute within the proxy service named
XSLTProxy
.
<proxy name="XSLTProxy" startOnLoad="true" transports="http https">
<description/>
<target>
<inSequence>
<xslt key="XSLTTest"/>
<log level="full"/>
<respond/>
</inSequence>
</target>
</proxy>
<localEntry key="XSLTTest">
<xsl:stylesheet version="2.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output method="xml" omit-xml-declaration="yes" indent="yes"/>
<xsl:template match="/">
<root>
<xsl:copy>
<xsl:text disable-output-escaping="yes"><![CDATA[</xsl:text>
<xsl:copy-of select="*"/>
<xsl:text disable-output-escaping="yes">]]></xsl:text>
</xsl:copy>
</root>
</xsl:template>
</xsl:stylesheet>
<description/>
</localEntry>
For example, pass the following payload to the XSLTProxy
proxy service of the above configuration.
<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/">
<soapenv:Header/>
<soapenv:Body>
<abc>testabc</abc>
</soapenv:Body>
</soapenv:Envelope>
You view the output with the CDATA displayed as follows in the Console logs of the WSO2 EI server.
INFO - LogMediator To: /services/XSLTProxy.XSLTProxyHttpSoap11Endpoint, WSAction: urn:mediate, SOAPAction: urn:mediate, MessageID: urn:uuid:266d380f-800f-479b-bee9-c30897efe562, Direction: request, Envelope: <?xml version='1.0' encoding='utf-8'?>
<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/">
<soapenv:Body>
<root xmlns="http://ws.apache.org/ns/synapse"><![CDATA[<abc xmlns="">testabc</abc>]]></root>
</soapenv:Body></soapenv:Envelope>
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