.
* There are three possible types of calls:
*
* Constructor:
* classns:new(arg1, arg2, ...)
*
* Static method:
* classns:method(arg1, arg2, ...)
*
* Instance method:
* classns:method(obj, arg1, arg2, ...)
*
* We use the following rules to determine the type of call made:
*
* - If the function name is "new", call the best constructor for
* class represented by the namespace URI
* - If the first argument to the function is of the class specified
* in the namespace or is a subclass of that class, look for the best
* method of the class specified in the namespace with the specified
* arguments. Compare all static and instance methods with the correct
* method name. For static methods, use all arguments in the compare.
* For instance methods, use all arguments after the first.
* - Otherwise, select the best static or instance method matching
* all of the arguments. If the best method is an instance method,
* call the function using a default object, creating it if needed.
*
*
* @param funcName Function name.
* @param args The arguments of the function call.
* @param methodKey A key that uniquely identifies this class and method call.
* @param exprContext The context in which this expression is being executed.
* @return the return value of the function evaluation.
* @throws TransformerException
*/
public Object callFunction (String funcName,
Vector args,
Object methodKey,
ExpressionContext exprContext)
throws TransformerException
{
Object[] methodArgs;
Object[][] convertedArgs;
Class[] paramTypes;
try
{
if (funcName.equals("new")) { // Handle constructor call
methodArgs = new Object[args.size()];
convertedArgs = new Object[1][];
for (int i = 0; i < methodArgs.length; i++)
{
methodArgs[i] = args.elementAt(i);
}
Constructor c = (Constructor) getFromCache(methodKey, null, methodArgs);
if (c != null)
{
try
{
paramTypes = c.getParameterTypes();
MethodResolver.convertParams(methodArgs, convertedArgs, paramTypes, exprContext);
return c.newInstance(convertedArgs[0]);
}
catch(Exception e)
{
// Must not have been the right one
}
}
c = MethodResolver.getConstructor(m_classObj,
methodArgs,
convertedArgs,
exprContext);
putToCache(methodKey, null, methodArgs, c);
return c.newInstance(convertedArgs[0]);
}
else
{
int resolveType;
Object targetObject = null;
methodArgs = new Object[args.size()];
convertedArgs = new Object[1][];
for (int i = 0; i < methodArgs.length; i++)
{
methodArgs[i] = args.elementAt(i);
}
Method m = (Method) getFromCache(methodKey, null, methodArgs);
if (m != null)
{
try
{
paramTypes = m.getParameterTypes();
MethodResolver.convertParams(methodArgs, convertedArgs, paramTypes, exprContext);
if (Modifier.isStatic(m.getModifiers()))
return m.invoke(null, convertedArgs[0]);
else
{
// This is tricky. We get the actual number of target arguments (excluding any
// ExpressionContext). If we passed in the same number, we need the implied object.
int nTargetArgs = convertedArgs[0].length;
if (ExpressionContext.class.isAssignableFrom(paramTypes[0]))
nTargetArgs--;
if (methodArgs.length <= nTargetArgs)
return m.invoke(m_defaultInstance, convertedArgs[0]);
else
return m.invoke(methodArgs[0], convertedArgs[0]);
}
}
catch(Exception e)
{
// Must not have been the right one
}
}
if (args.size() > 0)
{
targetObject = methodArgs[0];
if (targetObject instanceof XObject)
targetObject = ((XObject) targetObject).object();
if (m_classObj.isAssignableFrom(targetObject.getClass()))
resolveType = MethodResolver.DYNAMIC;
else
resolveType = MethodResolver.STATIC_AND_INSTANCE;
}
else
{
targetObject = null;
resolveType = MethodResolver.STATIC_AND_INSTANCE;
}
m = MethodResolver.getMethod(m_classObj,
funcName,
methodArgs,
convertedArgs,
exprContext,
resolveType);
putToCache(methodKey, null, methodArgs, m);
if (MethodResolver.DYNAMIC == resolveType) // First argument was object type
return m.invoke(targetObject, convertedArgs[0]);
else // First arg was not object. See if we need the implied object.
{
if (Modifier.isStatic(m.getModifiers()))
return m.invoke(null, convertedArgs[0]);
else
{
if (null == m_defaultInstance)
{
m_defaultInstance = m_classObj.newInstance();
}
return m.invoke(m_defaultInstance, convertedArgs[0]);
}
}
}
}
catch (InvocationTargetException ite)
{
Throwable realException = ite.getTargetException();
if (realException instanceof Exception)
throw new TransformerException((Exception) realException);
else
throw new TransformerException(ite);
}
catch (Exception e)
{
// e.printStackTrace();
throw new TransformerException(e);
}
}
/**
* Process a call to this extension namespace via an element. As a side
* effect, the results are sent to the TransformerImpl's result tree.
* We invoke the static or instance method in the class represented by
* by the namespace URI. If we don't already have an instance of this class,
* we create one upon the first call.
*
* @param localPart Element name's local part.
* @param element The extension element being processed.
* @param transformer Handle to TransformerImpl.
* @param stylesheetTree The compiled stylesheet tree.
* @param sourceTree The root of the source tree (but don't assume
* it's a Document).
* @param sourceNode The current context node.
* @param mode The current mode.
* @param methodKey A key that uniquely identifies this element call.
* @throws IOException if loading trouble
* @throws TransformerException if parsing trouble
*/
public void processElement(String localPart,
Element element,
TransformerImpl transformer,
Stylesheet stylesheetTree,
Node sourceTree,
Node sourceNode,
QName mode,
Object methodKey)
throws TransformerException, IOException
{
Object result = null;
Method m = (Method) getFromCache(methodKey, null, null);
if (null == m)
{
try
{
m = MethodResolver.getElementMethod(m_classObj, localPart);
if ( (null == m_defaultInstance) && !Modifier.isStatic(m.getModifiers()) )
m_defaultInstance = m_classObj.newInstance();
}
catch (Exception e)
{
// e.printStackTrace ();
throw new TransformerException (e.getMessage (), e);
}
putToCache(methodKey, null, null, m);
}
XSLProcessorContext xpc = new XSLProcessorContext(transformer,
stylesheetTree,
sourceTree,
sourceNode,
mode);
try
{
result = m.invoke(m_defaultInstance, new Object[] {xpc, element});
}
catch (Exception e)
{
// e.printStackTrace ();
throw new TransformerException (e.getMessage (), e);
}
if (result != null)
{
xpc.outputToResultTree (stylesheetTree, result);
}
}
}