org.mmbase.util.functions
Class FunctionProvider

java.lang.Object
  org.mmbase.util.functions.FunctionProvider

Direct Known Subclasses:

FunctionSet, IndexFunction, MMTable, Module, PatternNodeFunctionProvider

public abstract class FunctionProvider

extends Object

A function provider maintains a set of Function objects.

Since:

MMBase-1.8

Version:

$Id: FunctionProvider.java,v 1.11 2005/07/28 17:07:55 michiel Exp $

Author:

Pierre van Rooden

Field Summary

protected Map	functions
protected Function	getFunctions Every Function Provider provides least the 'getFunctions' function, which returns a Set of all functions which it provides.

Constructor Summary

FunctionProvider()
The constructor of an FunctionProvider two things.

Method Summary

void	addFunction(Function function) Adds a function to the FunctionProvider.
Parameters	createParameters(String functionName) Creates a new empty Parameters object for given function.
Function	getFunction(String functionName) Returns the Function object with given name.
Collection	getFunctions() Returns a Collection of all functions currently provided by the FunctionProvider.
Object	getFunctionValue(String functionName, List parameters) Executes a function, and returns the function value.
protected Function	newFunctionInstance(String name, Parameter[] parameters, ReturnType returnType)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

functions

protected Map functions

getFunctions

protected Function getFunctions

Every Function Provider provides least the 'getFunctions' function, which returns a Set of all functions which it provides.

Constructor Detail

FunctionProvider

public FunctionProvider()

The constructor of an FunctionProvider two things. It adds the 'getFunction' function, and it guesses other function using reflection.

To Do:

Should this last thing not only be done on MMObjectBuilders?

Method Detail

newFunctionInstance

protected Function newFunctionInstance(String name,
                                       Parameter[] parameters,
                                       ReturnType returnType)

addFunction

public void addFunction(Function function)

Adds a function to the FunctionProvider. So, you can implement any function and add it to the provider, to make it provide this function too.

createParameters

public Parameters createParameters(String functionName)

Creates a new empty Parameters object for given function.

Returns:

A new empty Parameters object, or null if no such function.

getFunctionValue

public Object getFunctionValue(String functionName,
                               List parameters)

Executes a function, and returns the function value.

Returns:

The function value or null if no such function.

getFunction

public Function getFunction(String functionName)

Returns the Function object with given name.

Returns:

Function object or null if no such function is provided.

getFunctions

public Collection getFunctions()

Returns a Collection of all functions currently provided by the FunctionProvider.