com.icl.saxon.expr
Class FunctionProxy

java.lang.Object
  |
  +--com.icl.saxon.expr.Expression
        |
        +--com.icl.saxon.expr.Function
              |
              +--com.icl.saxon.expr.FunctionProxy

public class FunctionProxy
extends Function

This class acts as a proxy for an extension function defined as a method in a user-defined class


Fields inherited from class com.icl.saxon.expr.Function
arguments
 
Fields inherited from class com.icl.saxon.expr.Expression
emptyVector, staticContext
 
Constructor Summary
FunctionProxy()
          Constructor: creates an uncommitted FunctionProxy
 
Method Summary
static Value convertJavaObjectToXPath(java.lang.Object result)
           
 Value eval(java.util.Vector arguments, Context context)
          Evaluate the function.
 int getDependencies()
          Determine which aspects of the context the expression depends on.
 java.lang.String getName()
          Get the name of the function
 boolean isAvailable(Name fullName)
          Determine whether the function is available.
 Expression reduce(int dependencies, Context context)
          Perform a partial evaluation of the expression, by eliminating specified dependencies on the context.
 void setMethod(Name fullName)
          setMethod: locates the external class and method to which this function relates.
 
Methods inherited from class com.icl.saxon.expr.Function
addArgument, checkArgumentCount, evaluate, getIntrinsicDependencies, newInstance, reduceIntrinsic, simplify, simplifyPureFunction, toString
 
Methods inherited from class com.icl.saxon.expr.Expression
containsReferences, enumerate, evaluateAsBoolean, evaluateAsNodeSet, evaluateAsNumber, evaluateAsString, getDataType, getStaticContext, isNumeric, isRelative, make, make, setStaticContext, usesCurrent
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Constructor Detail

FunctionProxy

public FunctionProxy()
Constructor: creates an uncommitted FunctionProxy
Method Detail

setMethod

public void setMethod(Name fullName)
setMethod: locates the external class and method to which this function relates. At this stage addArguments() will have been called, so the number of arguments is known. If no method of the required name is located, an exception is saved, but it is not thrown until an attempt is made to evaluate the function.
Parameters:
fullName - This identifies both the local name of the function and its namespace.

isAvailable

public boolean isAvailable(Name fullName)
Determine whether the function is available. This supports the extension-function-available function, and as such it is done without regard to the number of arguments.

getName

public java.lang.String getName()
Get the name of the function
Overrides:
getName in class Function
Following copied from class: com.icl.saxon.expr.Function
Returns:
the name of the function, as used in XSL expressions, but excluding its namespace prefix

getDependencies

public int getDependencies()
Determine which aspects of the context the expression depends on. The result is a bitwise-or'ed value composed from constants such as Context.VARIABLES and Context.CURRENT_NODE
Overrides:
getDependencies in class Function

reduce

public Expression reduce(int dependencies,
                         Context context)
                  throws org.xml.sax.SAXException
Perform a partial evaluation of the expression, by eliminating specified dependencies on the context.
Overrides:
reduce in class Function
Parameters:
dependencies - The dependencies to be removed
context - The context to be used for the partial evaluation
Returns:
a new expression that does not have any of the specified dependencies

eval

public Value eval(java.util.Vector arguments,
                  Context context)
           throws org.xml.sax.SAXException
Evaluate the function.
Overrides:
eval in class Function
Parameters:
arguments - A Vector, each of whose elements is a Value containing the value of a supplied argument to the function.
context - The context in which the function is to be evaluated
Returns:
a Value representing the result of the function.
Throws:
org.xml.sax.SAXException - if the function cannot be evaluated.

convertJavaObjectToXPath

public static Value convertJavaObjectToXPath(java.lang.Object result)
                                      throws org.xml.sax.SAXException