org.apache.xalan.extensions
Class ExtensionHandlerGeneral

java.lang.Object
  org.apache.xalan.extensions.ExtensionHandler
      org.apache.xalan.extensions.ExtensionHandlerGeneral

public class ExtensionHandlerGeneral

extends ExtensionHandler

Class handling an extension namespace for XPath. Provides functions to test a function's existence and call a function

Author:

Sanjiva Weerawarana (sanjiva@watson.ibm.com)

Field Summary

private static String	BSF_ENGINE BSFEngine package name
private static String	BSF_MANAGER BSFManager package name
private static Method	engineCall Engine call to invoke scripts
private static Method	engineExec Engine call to "compile" scripts
private Hashtable	m_elements elements of namespace
private Object	m_engine BSF manager used to run scripts
private Hashtable	m_functions functions of namespace
private Object	m_mgr Instance of Manager class
private String	m_scriptSrc script source to run (if any)
private String	m_scriptSrcURL URL of source of script (if any)
private static Class	managerClass Manager class
private static Method	mgrLoadScriptingEngine Manager load scripting engine
private static Integer	NEG1INT Negative one integer

Fields inherited from class org.apache.xalan.extensions.ExtensionHandler

m_namespaceUri, m_scriptLang

Constructor Summary

ExtensionHandlerGeneral(String namespaceUri, StringVector elemNames, StringVector funcNames, String scriptLang, String scriptSrcURL, String scriptSrc, String systemId)
Construct a new extension namespace handler given all the information needed.

Method Summary

Object	callFunction(String funcName, Vector args, Object methodKey, ExpressionContext exprContext) Process a call to a function.
boolean	isElementAvailable(String element) Tests whether a certain element name is known within this namespace.
boolean	isFunctionAvailable(String function) Tests whether a certain function name is known within this namespace.
void	processElement(String localPart, ElemTemplateElement element, TransformerImpl transformer, Stylesheet stylesheetTree, Object methodKey) Process a call to this extension namespace via an element.

Methods inherited from class org.apache.xalan.extensions.ExtensionHandler

getClassForName

Methods inherited from class java.lang.Object

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

Field Detail

m_scriptSrc

private String m_scriptSrc

script source to run (if any)

m_scriptSrcURL

private String m_scriptSrcURL

URL of source of script (if any)

m_functions

private Hashtable m_functions

functions of namespace

m_elements

private Hashtable m_elements

elements of namespace

m_mgr

private Object m_mgr

Instance of Manager class

m_engine

private Object m_engine

BSF manager used to run scripts

BSF_MANAGER

private static final String BSF_MANAGER

BSFManager package name

See Also:

Constant Field Values

managerClass

private static Class managerClass

Manager class

mgrLoadScriptingEngine

private static Method mgrLoadScriptingEngine

Manager load scripting engine

BSF_ENGINE

private static final String BSF_ENGINE

BSFEngine package name

See Also:

Constant Field Values

engineExec

private static Method engineExec

Engine call to "compile" scripts

engineCall

private static Method engineCall

Engine call to invoke scripts

NEG1INT

private static final Integer NEG1INT

Negative one integer

Constructor Detail

ExtensionHandlerGeneral

public ExtensionHandlerGeneral(String namespaceUri,
                               StringVector elemNames,
                               StringVector funcNames,
                               String scriptLang,
                               String scriptSrcURL,
                               String scriptSrc,
                               String systemId)
                        throws javax.xml.transform.TransformerException

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

Parameters:

namespaceUri - the extension namespace URI that I'm implementing

elemNames - Vector of element names

funcNames - string containing list of functions of extension NS

scriptLang - Scripting language of implementation

scriptSrcURL - URL of source script

scriptSrc - the actual script code (if any)

Throws:

javax.xml.transform.TransformerException

Method Detail

isFunctionAvailable

public boolean isFunctionAvailable(String function)

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

Specified by:

isFunctionAvailable in class ExtensionHandler

Parameters:

function - name of the function being tested

Returns:

true if its known, false if not.

isElementAvailable

public boolean isElementAvailable(String element)

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

Specified by:

isElementAvailable in class ExtensionHandler

Parameters:

element - name of the element being tested

Returns:

true if its known, false if not.

callFunction

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

Process a call to a function.

Specified by:

callFunction in class ExtensionHandler

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 void processElement(String localPart,
                           ElemTemplateElement element,
                           TransformerImpl transformer,
                           Stylesheet stylesheetTree,
                           Object methodKey)
                    throws javax.xml.transform.TransformerException,
                           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.

Specified by:

processElement in class ExtensionHandler

Parameters:

localPart - Element name's local part.

element - The extension element being processed.

transformer - Handle to TransformerImpl.

stylesheetTree - The compiled stylesheet tree.

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

IOException - if loading trouble

javax.xml.transform.TransformerException - if parsing trouble