Package org.jaxen

Interface Function

All Known Implementing Classes:

BooleanFunction, CeilingFunction, ConcatFunction, ContainsFunction, CountFunction, DocumentFunction, EndsWithFunction, EvaluateFunction, FalseFunction, FloorFunction, IdFunction, LangFunction, LastFunction, LocaleFunctionSupport, LocalNameFunction, LowerFunction, NameFunction, NamespaceUriFunction, NormalizeSpaceFunction, NotFunction, NumberFunction, PositionFunction, RoundFunction, StartsWithFunction, StringFunction, StringLengthFunction, SubstringAfterFunction, SubstringBeforeFunction, SubstringFunction, SumFunction, TranslateFunction, TrueFunction, UpperFunction

public interface Function

Interface for the extensible function framework.

NOTE: This class is not typically used directly, but is exposed for writers of extended XPath packages.

Implementations of Function are functors which are used to evaluate a function-call within an XPath expression.

Author:

bob mcwhirter

See Also:

FunctionContext

Method Summary

Modifier and Type	Method	Description
java.lang.Object	call(Context context, java.util.List args)	Evaluate this function.

Method Detail

call

java.lang.Object call(Context context,
                      java.util.List args)
               throws FunctionCallException

Evaluate this function.

Parameters:

context - the context at the point in the expression when the function is called

args - arguments provided to the function

Returns:

the result of evaluating the function; a List (node-set), Double, Boolean, or String

Throws:

FunctionCallException - if an XPath error occurs during evaluation; for instance, if the number or type of the arguments is incorrect