Package org.vedantatree.expressionoasis.extensions

Interface FunctionProvider

All Known Implementing Classes:

CustomFunctionProvider, CustomFunctionProvider, DefaultFunctionProvider, XMLFunctionProvider

public interface FunctionProvider

This class represents the interface for function providers for Expression Engine. Object of this type will be resolving the functions for any expression. It can support more than one functions.

Method Summary

Modifier and Type	Method	Description
Type	getFunctionType(String functionName, Type[] parameterTypes)	Gets the return type of the function.
ValueObject	getFunctionValue(String functionName, ValueObject[] parameters)	Gets the return value of function.
void	initialize(ExpressionContext expressionContext)	It initialize the Function provider with expression context and also gives a chance to pre-initialize any internal states for operations
boolean	supportsFunction(String functionName, Type[] parameterTypes)	Checks whether the this function provider supports any function or not.

Method Detail

initialize

void initialize(ExpressionContext expressionContext)
         throws ExpressionEngineException

It initialize the Function provider with expression context and also gives a chance to pre-initialize any internal states for operations

Parameters:

expressionContext - Context of current expression evaluation process

Throws:

ExpressionEngineException

getFunctionType

Type getFunctionType(String functionName,
                     Type[] parameterTypes)
              throws ExpressionEngineException

Gets the return type of the function.

Parameters:

functionName - the name of the function.

parameterTypes - the types of the parameters

Returns:

the return type of the function

Throws:

ExpressionEngineException - if anything goes wrong

getFunctionValue

ValueObject getFunctionValue(String functionName,
                             ValueObject[] parameters)
                      throws ExpressionEngineException

Gets the return value of function.

Parameters:

functionName - the name of the function

parameters - the parameters values of the function

Returns:

the return value of the function

Throws:

ExpressionEngineException - if anything goes wrong

supportsFunction

boolean supportsFunction(String functionName,
                         Type[] parameterTypes)
                  throws ExpressionEngineException

Checks whether the this function provider supports any function or not.

Parameters:

functionName - the name of the function

parameterTypes - the type of parameters for the function

Returns:

true if function provider supports the function false otherwise

Throws:

ExpressionEngineException - if anything goes wrong