This documentation is for WSO2 ESB version 4.5.0. View documentation for the latest release.

XSLT Mediator

The XSLT Mediator applies a specified XSLT transformation to a selected element of the current message payload. The source attribute specifies which element to be selected to apply the given XSLT transformation. In the case where the source element is not specified, it uses the first child of the soap body as the selected element. Optionally, parameters can be passed into the transformations through the property elements. These properties are corresponding to the XSL parameters and can be accessed during transformation by <xsl:param name="the name of the property"/>. The feature element defines any features which should be explicitly set to the TransformerFactory.

The feature: http://ws.apache.org/ns/synapse/transform/feature/dom turns on DOM-based transformations instead of serializing elements into Byte streams and/or temporary files. Though this can be better in performance than using byte streams, sometimes it may not work for all transformations.

Finally, the resource element can be used to resolve XSLT imports and includes from the repository. It works in exactly the same way as the corresponding element in a <proxy> definition (Proxy Service).



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>

The main elements and attributes:

  • source - Specifies which element to be selected to apply the given XSLT transformation. In the case where the source element is not specified, it uses the first child of the soap body as the selected element.
  • property - Allows optional parameters to be passed into the transformations. These properties are corresponding to the XSL parameters and can be accessed during transformation.
  • feature - Defines any features which should be explicitly set to the TransformerFactory. The feature, http://ws.apache.org/ns/synapse/transform/feature/dom turns on DOM-based transformations instead of serializing elements into Byte streams and/or temporary files. Though this can be better in performance than using byte streams, sometimes it may not work for all transformations.
  • resource - Resolves XSLT imports and includes from the repository. It works in exactly the same way as the corresponding element in a <proxy> definition (Proxy Service).

UI Configuration

  • Key Type - Specifies either to use Static or Dynamic Key type.
  • Key - Specifies the registry key to refer the XSLT to. This supports static and dynamic keys.
  • Source - Specifies in which part of the message (specified in XPath) the XSLT should be applied. The default is the SOAP body of the message. It can be added in the Namespace Editor.

    Tip

    You can click this link to add namespaces if you are providing an expression. You will be provided another panel named "Namespace Editor," where you can provide any number of namespace prefixes and URL that you have used in the XPath expression.

  • Properties of XSLT mediator - Manage the properties which would be referred from the XSLT in transformation (using get-property(prop-name) XPath extension function).
    • Property Name - Names the property.
    • Property Type - Specifies whether it is a static value or an XPath expression.
    • Value/Expression - Defines the static value or the XPath expression.
    • Action - Allows to delete the property.
  • Features of the XSLT mediator -Specifies the features to be enabled in the XSLT transformation. Read the introduction paragraph of this guide for an example feature.
    • Feature Name - Names the feature.
    • Feature Value - Specifies whether the feature is turn on (True) or Not (False).
    • Action - Allows to delete the feature.

Note

You can configure the Mediator using XML. Click on "switch to source view" in the "Mediator" window.


Example

<xslt xmlns="http://ws.apache.org/ns/synapse" key="transform/example.xslt" source="s11:Body/child" />

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.