Package org.apache.xpath.functions

Class FuncExtFunction

java.lang.Object
org.apache.xpath.Expression
org.apache.xpath.functions.Function
org.apache.xpath.functions.FuncExtFunction
All Implemented Interfaces:
Serializable, SourceLocator, ExpressionNode, XPathVisitable
public class FuncExtFunction
extends Function
An object of this class represents an extension call expression. When the expression executes, it calls ExtensionsTable#extFunction, and then converts the result to the appropriate XObject.
See Also:
Serialized Form

  • Constructor Details

    • FuncExtFunction

      public FuncExtFunction​(String namespace, String extensionName, Object methodKey)
      Create a new FuncExtFunction based on the qualified name of the extension, and a unique method key.
      Parameters:
      namespace - The namespace for the extension function, which should not normally be null or empty.
      extensionName - The local name of the extension.
      methodKey - Unique method key, which is passed to ExtensionsTable#extFunction in order to allow caching of the method.

  • Method Details

    • fixupVariables

      public void fixupVariables​(Vector vars, int globalsSize)
      This function is used to fixup variables from QNames to stack frame indexes at stylesheet build time.
      Specified by:
      fixupVariables in class Expression
      Parameters:
      vars - List of QNames that correspond to variables. This list should be searched backwards for the first qualified name that corresponds to the variable reference qname. The position of the QName in the vector from the start of the vector will be its position in the stack frame (but variables above the globalsTop value will need to be offset to the current stack frame). NEEDSDOC @param globalsSize

    • getNamespace

      public String getNamespace()
      Return the namespace of the extension function.
      Returns:
      The namespace of the extension function.

    • getFunctionName

      public String getFunctionName()
      Return the name of the extension function.
      Returns:
      The name of the extension function.

    • getMethodKey

      public Object getMethodKey()
      Return the method key of the extension function.
      Returns:
      The method key of the extension function.

    • getArg

      public Expression getArg​(int n)
      Return the nth argument passed to the extension function.
      Parameters:
      n - The argument number index.
      Returns:
      The Expression object at the given index.

    • getArgCount

      public int getArgCount()
      Return the number of arguments that were passed into this extension function.
      Returns:
      The number of arguments.

    • execute

      public XObject execute​(XPathContext xctxt) throws TransformerException
      Execute the function. The function must return a valid object.
      Overrides:
      execute in class Function
      Parameters:
      xctxt - The current execution context.
      Returns:
      A valid XObject.
      Throws:
      TransformerException

    • setArg

      public void setArg​(Expression arg, int argNum) throws WrongNumberArgsException
      Set an argument expression for a function. This method is called by the XPath compiler.
      Overrides:
      setArg in class Function
      Parameters:
      arg - non-null expression that represents the argument.
      argNum - The argument number index.
      Throws:
      WrongNumberArgsException - If the argNum parameter is beyond what is specified for this function.

    • checkNumberArgs

      public void checkNumberArgs​(int argNum) throws WrongNumberArgsException
      Check that the number of arguments passed to this function is correct.
      Overrides:
      checkNumberArgs in class Function
      Parameters:
      argNum - The number of arguments that is being passed to the function.
      Throws:
      WrongNumberArgsException

    • callArgVisitors

      public void callArgVisitors​(XPathVisitor visitor)
      Call the visitors for the function arguments.
      Overrides:
      callArgVisitors in class Function

    • exprSetParent

      public void exprSetParent​(ExpressionNode n)
      Set the parent node. For an extension function, we also need to set the parent node for all argument expressions.
      Specified by:
      exprSetParent in interface ExpressionNode
      Overrides:
      exprSetParent in class Expression
      Parameters:
      n - The parent node

    • reportWrongNumberArgs

      protected void reportWrongNumberArgs() throws WrongNumberArgsException
      Constructs and throws a WrongNumberArgException with the appropriate message for this function object. This class supports an arbitrary number of arguments, so this method must never be called.
      Overrides:
      reportWrongNumberArgs in class Function
      Throws:
      WrongNumberArgsException

    • toString

      public String toString()
      Return the name of the extesion function in string format
      Overrides:
      toString in class Object
      Returns:
      a printable representation of this object.