Parameters and ContextParameters and Context
Parameters and Context in the NetKernel API
Home > Books > Solutions Developer Guide > Scripting Languages > Parameters and Context

Rate this page:
Really useful
Satisfactory
Not helpful
Confusing
Incorrect
Unsure
Extra comments:


Context and Parameters

Each request exists within an operational context. The context includes any argument values for named parameters passed to a service. For example the xslt service obtains the XSL stylesheet from a resource associated with the operator parameter and it obtains the XML document to be styled from a resource associated with the operand parameter:

active:xslt+operator@ffcpl:/style.xsl+operand@ffcpl:/source.xml

Script language programs may obtain argument values through an instance of INKFConvenienceHelper provided as a local variable named "context". For example, when a JavaScript program is call with the following URI address:

active:javascript+operator@ffcpl:/program.js+data@ffcpl:/data.xml

the program is identified as the operator argument and the data argument is the URI address ffcpl:/data.xml. This is set up inside NetKernel as two nested contexts. In the inner context the JavaScript execution engine requests the program to be run by making a resource request for the URI provided as the operator argument. In the outer context the parameter data has an argument value URI identifying an XML document which the JavaScript program processes.

The following JavaScript program fragment illustrates how to obtain the resource identified by the data parameter value.

importPackage(Packages.org.ten60.netkernel.xml.representation);
importPackage(Packages.org.ten60.netkernel.layer1.representation);
importPackage(Packages.com.ten60.netkernel.urii.aspect);
importPackage(Packages.java.lang);

xoa=context.sourceAspect("this:param:data", IAspectXmlObject);
© 2003-2007, 1060 Research Limited. 1060 registered trademark, NetKernel trademark of 1060 Research Limited.