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 and Description
Object	call(Context context, List args) Evaluate this function.

Method Detail

call

Object call(Context context,
            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