AbstractFunction (MMBase 1.9-SNAPSHOT

java.lang.Object
- org.mmbase.util.functions.AbstractFunction<R>

All Implemented Interfaces:

Serializable, Comparable<Function<R>>, Function<R>

Direct Known Subclasses:

BeanFunction, FileServlet.DirectoryFunction, MethodFunction, NodeFunction, ProcessorModule.GetNodeListFunction, ProcessorModule.ProcessFunction, ProcessorModule.ReplaceFunction, SetFunction
```
public abstract class AbstractFunction<R>
extends Object
implements Function<R>, Comparable<Function<R>>, Serializable
```
An abstract representation of a piece of functionality (a 'function'). A function has a name, a return type, and a parameter-definition (which is a Parameter array). The goal of a Function object is to call its getFunctionValue(Parameters) method, which executes it, given the specified parameters. The Parameter definition and ReturnType can be passed into your implementation using the constructor. The implementation must be provided by implementing getFunctionValue(org.mmbase.util.functions.Parameters).

Since:

MMBase-1.8

Version:

$Id$

Author:

Daniel Ockeloen, Michiel Meeuwissen

See Also:

Parameter, Parameters, Serialized Form

Field Summary

Fields
Modifier and Type Field and Description

protected boolean autoReturnType

protected String name

protected ReturnType<R> returnType

Fields
Modifier and Type	Field and Description
`protected boolean`	`autoReturnType`
`protected String`	`name`
`protected ReturnType<R>`	`returnType`

Constructor Summary

Constructors
Constructor and Description
`AbstractFunction(String name, Parameter<?>... def)` Determines the ReturnType automaticly using the return type of `getFunctionValue(Parameters)`.
`AbstractFunction(String name, Parameter<?>[] def, ReturnType<R> returnType)` Constructor for Function objects.

Method Summary

All Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method and Description
`int`	`compareTo(Function<R> fun)`
`Parameters`	`createParameters()` Creates an empty 'Parameters' object for you, which you have to fill and feed back to getFunctionValue
`boolean`	`equals(Object o)`
`String`	`getDescription()`
`abstract R`	`getFunctionValue(Parameters parameters)` Executes the defined function supplying the given arguments.
`R`	`getFunctionValueWithList(List<?> parameters)` Executes the defined function supplying the given List of arguments.
`String`	`getName()` A function must have a name.
`Parameter<?>[]`	`getParameterDefinition()`
`ReturnType<R>`	`getReturnType()`
`int`	`hashCode()`
`void`	`setDescription(String description)` For documentational purposes a function object needs a description too.
`void`	`setParameterDefinition(Parameter<?>[] params)` A function object is of no use, as long as it lacks a definition.
`void`	`setReturnType(ReturnType<R> type)` Sets the ReturnType for this function if not set already.
`String`	`toString()`

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

- Field Detail
  - name
```
protected final String name
```
  - returnType
```
protected ReturnType<R> returnType
```
  - autoReturnType
```
protected boolean autoReturnType
```
- Constructor Detail
  - AbstractFunction
```
public AbstractFunction(String name,
                        Parameter<?>[] def,
                        ReturnType<R> returnType)
```
    Constructor for Function objects.
    
    Parameters:
    
    name - Every function must have a name
    
    def - Every function must have a parameter definition. It can be left null and then filled later by setParameterDefinition(org.mmbase.util.functions.Parameter<?>[])
    
    returnType - Every function must also specify its return type. It can be left null and then filled later by setReturnType(org.mmbase.util.functions.ReturnType<R>)
  - AbstractFunction
```
public AbstractFunction(String name,
                        Parameter<?>... def)
```
    Determines the ReturnType automaticly using the return type of getFunctionValue(Parameters).
    
    Since:
    
    MMBase-1.9
- Method Detail
  - createParameters
```
public Parameters createParameters()
```
    Creates an empty 'Parameters' object for you, which you have to fill and feed back to getFunctionValue
    
    Specified by:
    
    createParameters in interface Function<R>
    
    See Also:
    
    getFunctionValue(Parameters)
  - getFunctionValue
```
public abstract R getFunctionValue(Parameters parameters)
```
    Executes the defined function supplying the given arguments.
    
    Specified by:
    
    getFunctionValue in interface Function<R>
    
    Parameters:
    
    parameters - The parameters for the function. To specify an empty parameter list use Parameters.VOID. Implementors are encouraged to support null too.
    
    Returns:
    
    The function value, which can be of any type compatible to getReturnType()
    
    See Also:
    
    createParameters()
  - getFunctionValueWithList
```
public final R getFunctionValueWithList(List<?> parameters)
```
    Executes the defined function supplying the given List of arguments. This is a convenience method, as the List is mapped to a Parameters type and passed to getFunctionValue(Parameters).
    
    Specified by:
    
    getFunctionValueWithList in interface Function<R>
    
    Parameters:
    
    parameters - The parameters for the function. To specify an empty parameter list use Parameters.VOID.
    
    Returns:
    
    The function value, which can be of any type compatible to getReturnType()
  - setDescription
```
public void setDescription(String description)
```
    For documentational purposes a function object needs a description too.
    
    Specified by:
    
    setDescription in interface Function<R>
  - getDescription
```
public String getDescription()
```
    Specified by:
    
    getDescription in interface Function<R>
    
    See Also:
    
    setDescription(String)
  - getName
```
public String getName()
```
    A function must have a name. This is the name which was used to aquire the function object.
    
    Specified by:
    
    getName in interface Function<R>
    
    Returns:
    
    The function's name, never null
  - getParameterDefinition
```
public Parameter<?>[] getParameterDefinition()
```
    Specified by:
    
    getParameterDefinition in interface Function<R>
    
    Returns:
    
    The currently set Parameter definition array, or null if not set already.
  - setParameterDefinition
```
public void setParameterDefinition(Parameter<?>[] params)
```
    A function object is of no use, as long as it lacks a definition.
    
    Specified by:
    
    setParameterDefinition in interface Function<R>
    
    Parameters:
    
    params - An array of Parameter objects.
    
    Throws:
    
    IllegalStateException - if there was already set a parameter defintion for this function object.
  - getReturnType
```
public ReturnType<R> getReturnType()
```
    Specified by:
    
    getReturnType in interface Function<R>
    
    Returns:
    
    The currently set ReturnType, or null if not set already.
  - setReturnType
```
public void setReturnType(ReturnType<R> type)
```
    Sets the ReturnType for this function if not set already.
    
    Specified by:
    
    setReturnType in interface Function<R>
    
    Parameters:
    
    type - A ReturnType object. For void functions that could be ReturnType.VOID.
    
    Throws:
    
    IllegalStateException - if there was already set a return type for this function object.
  - compareTo
```
public int compareTo(Function<R> fun)
```
    Specified by:
    
    compareTo in interface Comparable<Function<R>>
  - equals
```
public boolean equals(Object o)
```
    Overrides:
    
    equals in class Object
  - hashCode
```
public int hashCode()
```
    Overrides:
    
    hashCode in class Object
    
    See Also:
    
    Object.hashCode()
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object

Class AbstractFunction<R>

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

name

returnType

autoReturnType

Constructor Detail

AbstractFunction

AbstractFunction

Method Detail

createParameters

getFunctionValue

getFunctionValueWithList

setDescription

getDescription

getName

getParameterDefinition

setParameterDefinition

getReturnType

setReturnType

compareTo

equals

hashCode

toString