org.apache.xalan.extensions
Class ExtensionsTable

java.lang.Object
  org.apache.xalan.extensions.ExtensionsTable

public class ExtensionsTable

extends Object

Class holding a table registered extension namespace handlers

Field Summary

Hashtable	m_extensionFunctionNamespaces Table of extensions that may be called from the expression language via the call(name, ...) function.
private StylesheetRoot	m_sroot The StylesheetRoot associated with this extensions table.

Constructor Summary

ExtensionsTable(StylesheetRoot sroot)
The constructor (called from TransformerImpl) registers the StylesheetRoot for the transformation and instantiates an ExtensionHandler for each extension namespace.

Method Summary

void	addExtensionNamespace(String uri, ExtensionHandler extNS) Register an extension namespace handler.
boolean	elementAvailable(String ns, String elemName) Execute the element-available() function.
Object	extFunction(String ns, String funcName, Vector argVec, Object methodKey, ExpressionContext exprContext) Handle an extension function.
boolean	functionAvailable(String ns, String funcName) Execute the function-available() function.
ExtensionHandler	get(String extns) Get an ExtensionHandler object that represents the given namespace.

Methods inherited from class java.lang.Object

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

Field Detail

m_extensionFunctionNamespaces

public Hashtable m_extensionFunctionNamespaces

Table of extensions that may be called from the expression language via the call(name, ...) function. Objects are keyed on the call name.

m_sroot

private StylesheetRoot m_sroot

The StylesheetRoot associated with this extensions table.

Constructor Detail

ExtensionsTable

public ExtensionsTable(StylesheetRoot sroot)
                throws javax.xml.transform.TransformerException

The constructor (called from TransformerImpl) registers the StylesheetRoot for the transformation and instantiates an ExtensionHandler for each extension namespace.

Method Detail

get

public ExtensionHandler get(String extns)

Get an ExtensionHandler object that represents the given namespace.

Parameters:

extns - A valid extension namespace.

Returns:

ExtensionHandler object that represents the given namespace.

addExtensionNamespace

public void addExtensionNamespace(String uri,
                                  ExtensionHandler extNS)

Register an extension namespace handler. This handler provides functions for testing whether a function is known within the namespace and also for invoking the functions.

Parameters:

uri - the URI for the extension.

extNS - the extension handler.

functionAvailable

public boolean functionAvailable(String ns,
                                 String funcName)
                          throws javax.xml.transform.TransformerException

Execute the function-available() function.

Parameters:

ns - the URI of namespace in which the function is needed

funcName - the function name being tested

Returns:

whether the given function is available or not.

Throws:

javax.xml.transform.TransformerException

elementAvailable

public boolean elementAvailable(String ns,
                                String elemName)
                         throws javax.xml.transform.TransformerException

Execute the element-available() function.

Parameters:

ns - the URI of namespace in which the function is needed

elemName - name of element being tested

Returns:

whether the given element is available or not.

Throws:

javax.xml.transform.TransformerException

extFunction

public Object extFunction(String ns,
                          String funcName,
                          Vector argVec,
                          Object methodKey,
                          ExpressionContext exprContext)
                   throws javax.xml.transform.TransformerException

Handle an extension function.

Parameters:

ns - the URI of namespace in which the function is needed

funcName - the function name being called

argVec - arguments to the function in a vector

methodKey - a unique key identifying this function instance in the stylesheet

exprContext - a context which may be passed to an extension function and provides callback functions to access various areas in the environment

Returns:

result of executing the function

Throws:

javax.xml.transform.TransformerException