org.apache.xalan.extensions
Class ExtensionsTable

java.lang.Object
  extended byorg.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