org.apache.xalan.extensions
Class ExtensionHandlerJavaPackage
java.lang.Object
|
+--org.apache.xalan.extensions.ExtensionHandler
|
+--org.apache.xalan.extensions.ExtensionHandlerJava
|
+--org.apache.xalan.extensions.ExtensionHandlerJavaPackage
- public class ExtensionHandlerJavaPackage
- extends ExtensionHandlerJava
Represents an extension namespace for XPath that handles java packages
that may be fully or partially specified.
It is recommended that the class URI be of one of the following forms:
xalan://partial.class.name
xalan://
http://xml.apache.org/xalan/java (which is the same as xalan://)
However, we do not enforce this. If the class name contains a
a /, we only use the part to the right of the rightmost slash.
In addition, we ignore any "class:" prefix.
Provides functions to test a function's existence and call a function.
Also provides functions to test an element's existence and call an
element.
- Usage:
- **For internal use only**
Constructor Summary |
ExtensionHandlerJavaPackage(java.lang.String namespaceUri,
java.lang.String scriptLang,
java.lang.String className)
Construct a new extension namespace handler given all the information
needed. |
Methods inherited from class java.lang.Object |
equals,
getClass,
hashCode,
notify,
notifyAll,
toString,
wait,
wait,
wait |
ExtensionHandlerJavaPackage
public ExtensionHandlerJavaPackage(java.lang.String namespaceUri,
java.lang.String scriptLang,
java.lang.String className)
- Construct a new extension namespace handler given all the information
needed.
- Parameters:
namespaceUri
- the extension namespace URI that I'm implementingscriptLang
- language of code implementing the extensionclassName
- the beginning of the class name of the class. This
should be followed by a dot (.)
isFunctionAvailable
public boolean isFunctionAvailable(java.lang.String function)
- Tests whether a certain function name is known within this namespace.
Since this is for a package, we concatenate the package name used when
this handler was created and the function name specified in the argument.
There is
no information regarding the arguments to the function call or
whether the method implementing the function is a static method or
an instance method.
- Parameters:
function
- name of the function being tested- Returns:
- true if its known, false if not.
- Overrides:
- isFunctionAvailable in class ExtensionHandler
isElementAvailable
public boolean isElementAvailable(java.lang.String element)
- Tests whether a certain element name is known within this namespace.
Looks for a method with the appropriate name and signature.
This method examines both static and instance methods.
- Parameters:
element
- name of the element being tested- Returns:
- true if its known, false if not.
- Overrides:
- isElementAvailable in class ExtensionHandler
callFunction
public java.lang.Object callFunction(java.lang.String funcName,
java.util.Vector args,
java.lang.Object methodKey,
ExpressionContext exprContext)
throws TransformerException
- Process a call to a function in the package java namespace.
There are three possible types of calls:
Constructor:
packagens:class.name.new(arg1, arg2, ...)
Static method:
packagens:class.name.method(arg1, arg2, ...)
Instance method:
packagens:method(obj, arg1, arg2, ...)
We use the following rules to determine the type of call made:
- If the function name ends with a ".new", call the best constructor for
class whose name is formed by concatenating the value specified on
the namespace with the value specified in the function invocation
before ".new".
- If the function name contains a period, call the best static method "method"
in the class whose name is formed by concatenating the value specified on
the namespace with the value specified in the function invocation.
- Otherwise, call the best instance method "method"
in the class whose name is formed by concatenating the value specified on
the namespace with the value specified in the function invocation.
Note that a static method of the same
name will not be called in the current implementation. This
module does not verify that the obj argument is a member of the
package namespace.
- 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:
- TransformerException - if parsing trouble
- Overrides:
- callFunction in class ExtensionHandler
callFunction
public java.lang.Object callFunction(FuncExtFunction extFunction,
java.util.Vector args,
ExpressionContext exprContext)
throws TransformerException
- Process a call to an XPath extension function
- Parameters:
extFunction
- The XPath extension functionargs
- The arguments of the function call.exprContext
- The context in which this expression is being executed.- Returns:
- the return value of the function evaluation.
- Throws:
- TransformerException -
- Overrides:
- callFunction in class ExtensionHandler
processElement
public void processElement(java.lang.String localPart,
ElemTemplateElement element,
TransformerImpl transformer,
Stylesheet stylesheetTree,
java.lang.Object methodKey)
throws 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.
For this namespace, only static element methods are currently supported.
If instance methods are needed, please let us know your requirements.
- 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 element call.- Throws:
- java.io.IOException - if loading trouble
- TransformerException - if parsing trouble
- Overrides:
- processElement in class ExtensionHandler
Copyright © 2006 Apache XML Project. All Rights Reserved.