In SOA 11g, you can create a XSLT mapper that uses multiple sources as
the input. To implement a multi-source mapper, just follow
the instructions below,
Drag and drop a Transform Activity to a BPEL process
Double-click on
the Transform Activity,
the Transform dialog window appears.
Add source variables by clicking
the Add icon and selecting
the variable and part of
the variable as needed. You can select multiple input variables.
The first variable represents
the main XML input to
the XSL mapping, while additional variables that are added here are defined in
the XSL mapping as input parameters.
Select
the target variable and its part if available.
Specify
the mapper file name,
the default file name is xsl/Transformation_%SEQ%.xsl, where %SEQ% represents
the sequence number of
the mapper.
Click OK,
the xls file will be opened in
the graphical mode. You can map
the sources to
the target as usual.
Open
the mapper source code, you will notice
the variable representing
the additional source payload, is defined as
the input parameter in
the map source spec and body<mapSources> <source type="XSD"> <schema location="../xsd/po.xsd"/> <rootElement name="PurchaseOrder" namespace="http://www.oracle.com/pcbpel/po"/> </source> <source type="XSD"> <schema location="../xsd/customer.xsd"/> <rootElement name="Customer" namespace="http://www.oracle.com/pcbpel/Customer"/> <param name="v_customer" /> </source> </mapSources>...<xsl:param name="v_customer"/>
Let's take a look at
the BPEL source code used to execute xslt mapper. <assign name="Transform_1"> <bpelx:annotation> <bpelx:pattern>transformation</bpelx:pattern> </bpelx:annotation> <copy> <from expression="ora:doXSLTransformForDoc('xsl/Transformation_1.xsl',bpws:getVariableData('v_po'),'v_customer',bpws:getVariableData('v_customer'))"/> <to variable="v_invoice"/> </copy> </assign>
You will see BPEL uses ora:doXSLTransformForDoc XPath function to execute
the XSLT mapper.This function returns
the result of XSLT transformation when
the xslt template matching
the document.
The signature of this function is ora:doXSLTransformForDoc(template,input, [paramQName, paramValue]*).Wheretemplate is
the XSLT mapper nameinput is
the string representation of xml input, paramQName is
the parameter defined in
the xslt mapper as
the additional sourceparameterValue is
the additional source payload.
You can add more sources to
the mapper at
the later stage, but you have to modify
the ora:doXSLTransformForDoc in
the BPEL source code and make sure it passes correct parameter and its value pair that reflects
the changes in
the XSLT mapper.So
the best practices are :
create
the variables before creating
the mapping file, therefore you can add multiple sources when you define
the transformation in
the first place, which is more straightforward than adding them later on.
Review ora:doXSLTransformForDoc code in
the BPEL source and make sure it passes
the correct parameters to
the mapper.
