This processor is deprecated. It still ships with Orbeon Forms for backward compatibility with existing applications using this processor. However, if you are writing new code, or changing code, you should instead look at the
Submission processor, which allows you to call web and REST services, while reusing the
<xforms:submission> construct, and providing you all the power of the XForms submission from XPL.
Introduction
The Delegation processor allows calling services implemented as:
- A JavaBean
- An EJB
- A Web service
The main benefit of the Delegation processor is that you do not need to implement
your own XML processor in Java to call services.
Inputs and outputs
| Type |
Name |
Purpose |
Mandatory |
| Input |
interface |
The interface input declares services that you can then call in the
call input. You define one or more service identifiers and map those
to a given JavaBean, EJB or Web service. You also need to provide information
that the delegation processor needs to call
the service: for instance a JNDI name for an EJB or a class name for a
JavaBean.
The interface input is the only document with information
specific to the service type (EJB, Web service or JavaBean). This means that
if, at some point, a service is moved from, say, a JavaBean to an EJB, ohly
the interface has to be modified, but not the call input.
|
Yes |
| Input |
call |
-
The
call input contains an XML document which is a
template containing <delegation:execute>
elements.
-
The
<delegation:execute> element must be in the
http://orbeon.org/oxf/xml/delegation namespace. The
delegation prefix is usually mapped to this namespace.
-
Each
<delegation:execute> element specifies a
service to be called and the parameters to be sent to that service.
-
For calls to JavaBeans and EJBs in particular, it is important that the
resulting document be a well-formed XML document. In particular, the
resulting document must have a root element. In this case, always be
sure that your
call input contains at least one root
element around <delegation:execute> elements.
|
Yes |
| Output |
data |
The data output produces a document based on the
call input where the <delegation:execute>
elements have been replaced with the value returned by the service.
|
Yes |
Calling a JavaBean
This is an example of using the Delegation processor to call a JavaBean:
<p:processor xmlns:p="http://www.orbeon.com/oxf/pipeline" xmlns:xforms="http://www.w3.org/2002/xforms" xmlns:delegation="http://orbeon.org/oxf/xml/delegation" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" name="oxf:delegation">
<p:input name="interface">
<config>
<service id="my-service" type="javabean" class="MyClass"/>
</config>
</p:input>
<p:input name="call">
<result>
<delegation:execute service="my-service" operation="myMethod">
<param1 xsi:type="xs:string">param1</param1>
</delegation:execute>
</result>
</p:input>
<p:output name="data" id="result"/>
</p:processor>
-
The
interface input declares the JavaBean to call:
-
The
call input defines the method to call and the parameters
to pass:
Calling an EJB
This is an example of using the Delegation processor to call an EJB:
<p:processor xmlns:p="http://www.orbeon.com/oxf/pipeline" xmlns:xforms="http://www.w3.org/2002/xforms" xmlns:delegation="http://orbeon.org/oxf/xml/delegation" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" name="oxf:delegation">
<p:input name="interface">
<config>
<service id="creditcard-validation" type="stateless-ejb" uri="java:comp/env/ejb/creditcard-validation"/>
</config>
</p:input>
<p:input name="call">
<delegation:execute service="creditcard-validation" operation="validate">
<number xsi:type="xs:string">1234123412341234</number>
<type xsi:type="xs:string">visa</type>
</delegation:execute>
</p:input>
<p:output name="data" id="result"/>
</p:processor>
-
The
interface input declares the EJB that will be called:
-
The
call input defines the method to be called and the parameters:
Calling a web service
Example: rpc-style
<p:processor xmlns:p="http://www.orbeon.com/oxf/pipeline" xmlns:xforms="http://www.w3.org/2002/xforms" xmlns:delegation="http://orbeon.org/oxf/xml/delegation" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" name="oxf:delegation">
<p:input name="interface">
<config>
<service id="quotes" type="webservice" style="rpc" endpoint="http://www.scdi.org/~avernet/webservice/">
<operation nsuri="urn:avernet" name="getRandomQuote" encodingStyle="http://schemas.xmlsoap.org/soap/encoding/"/>
</service>
</config>
</p:input>
<p:input name="call">
<delegation:execute service="quotes" operation="getRandomQuote"/>
</p:input>
<p:output name="data" id="result"/>
</p:processor>
Example: document-style
<p:processor xmlns:p="http://www.orbeon.com/oxf/pipeline" xmlns:xforms="http://www.w3.org/2002/xforms" xmlns:delegation="http://orbeon.org/oxf/xml/delegation" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" name="oxf:delegation">
<p:input name="interface">
<config>
<service id="stock-quote" type="webservice" style="document" endpoint="http://ws.cdyne.com/delayedstockquote/delayedstockquote.asmx">
<operation name="get-quote" soap-action="http://ws.cdyne.com/GetQuote"/>
</service>
</config>
</p:input>
<p:input name="call">
<delegation:execute service="stock-quote" operation="get-quote" xsl:version="2.0">
<m:GetQuote xmlns:m="http://ws.cdyne.com/">
<m:StockSymbol>IBM</m:StockSymbol>
<m:LicenseKey>0</m:LicenseKey>
</m:GetQuote>
</delegation:execute>
</p:input>
<p:output name="data" id="result"/>
</p:processor>
Usage
-
The
interface input declares the Web service to be called:
-
In the
call input:
