WebLogic Server 6.1 API Reference

weblogic.apache.xalan.extensions
Class ExtensionHandler

java.lang.Object
  |
  +--weblogic.apache.xalan.extensions.ExtensionHandler

Direct Known Subclasses:

ExtensionHandlerGeneral, ExtensionHandlerJava

public abstract class ExtensionHandler

extends java.lang.Object

Abstract base class for handling an extension namespace for XPath. Provides functions to test a function's existence and call a function. Also provides functions for calling an element and testing for an element's existence.

This class is based on an implementation from the Apache XML Project. In future releases the XML parser, XSLT processor, and associated classes will likely be updated to be based on a later version of the Apache implementations. Since Apache does not guarantee backwards compatibility between versions of their software, we cannot guarantee backwards compatibility of any of the classes contained in the weblogic.apache package or sub-packages.

Author:

Sanjiva Weerawarana (sanjiva@watson.ibm.com)

Field Summary

protected java.lang.String	m_namespaceUri uri of the extension namespace
protected java.lang.String	m_scriptLang scripting language of implementation

Constructor Summary

protected

ExtensionHandler(java.lang.String namespaceUri, java.lang.String scriptLang) Construct a new extension namespace handler given all the information needed.

Method Summary

abstract java.lang.Object	callFunction(java.lang.String funcName, java.util.Vector args, java.lang.Object methodKey, ExpressionContext exprContext) Process a call to a function.
abstract boolean	isElementAvailable(java.lang.String element) Tests whether a certain element name is known within this namespace.
abstract boolean	isFunctionAvailable(java.lang.String function) Tests whether a certain function name is known within this namespace.
abstract void	processElement(java.lang.String localPart, org.w3c.dom.Element element, TransformerImpl transformer, Stylesheet stylesheetTree, org.w3c.dom.Node sourceTree, org.w3c.dom.Node sourceNode, QName mode, java.lang.Object methodKey) Process a call to this extension namespace via an element.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

m_namespaceUri

protected java.lang.String m_namespaceUri

uri of the extension namespace

m_scriptLang

protected java.lang.String m_scriptLang

scripting language of implementation

Constructor Detail

ExtensionHandler

protected ExtensionHandler(java.lang.String namespaceUri,
                           java.lang.String scriptLang)

Construct a new extension namespace handler given all the information needed.

Parameters:

namespaceUri - the extension namespace URI that I'm implementing

scriptLang - language of code implementing the extension

Method Detail

isFunctionAvailable

public abstract boolean isFunctionAvailable(java.lang.String function)

Tests whether a certain function name is known within this namespace.

Parameters:

function - name of the function being tested

Returns:

true if its known, false if not.

isElementAvailable

public abstract boolean isElementAvailable(java.lang.String element)

Tests whether a certain element name is known within this namespace.

Parameters:

function - name of the function being tested

element - Name of element to check

Returns:

true if its known, false if not.

callFunction

public abstract java.lang.Object callFunction(java.lang.String funcName,
                                              java.util.Vector args,
                                              java.lang.Object methodKey,
                                              ExpressionContext exprContext)
                                       throws javax.xml.transform.TransformerException

Process a call to a function.

Parameters:

funcName - Function name.

args - The arguments of the function call.

methodKey - A key that uniquely identifies this class and method call.

exprContext - The context in which this expression is being executed.

Returns:

the return value of the function evaluation.

Throws:

javax.xml.transform.TransformerException - if parsing trouble

processElement

public abstract void processElement(java.lang.String localPart,
                                    org.w3c.dom.Element element,
                                    TransformerImpl transformer,
                                    Stylesheet stylesheetTree,
                                    org.w3c.dom.Node sourceTree,
                                    org.w3c.dom.Node sourceNode,
                                    QName mode,
                                    java.lang.Object methodKey)
                             throws javax.xml.transform.TransformerException,
                                    java.io.IOException

Process a call to this extension namespace via an element. As a side effect, the results are sent to the TransformerImpl's result tree.

Parameters:

localPart - Element name's local part.

element - The extension element being processed.

transformer - Handle to TransformerImpl.

stylesheetTree - The compiled stylesheet tree.

mode - The current mode.

sourceTree - The root of the source tree (but don't assume it's a Document).

sourceNode - The current context node.

methodKey - A key that uniquely identifies this class and method call.

Throws:

XSLProcessorException - thrown if something goes wrong while running the extension handler.

MalformedURLException - if loading trouble

FileNotFoundException - if loading trouble

java.io.IOException - if loading trouble

javax.xml.transform.TransformerException - if parsing trouble