org.mmbase.util.functions
Class NodeFunction

java.lang.Object
  org.mmbase.util.functions.AbstractFunction
      org.mmbase.util.functions.NodeFunction

All Implemented Interfaces:

Comparable, Function, Serializable

Direct Known Subclasses:

PatternNodeFunctionProvider.PatternNodeFunction

public abstract class NodeFunction

extends AbstractFunction

A NodeFunction represents a function on a node instances of this builder. This means that it always has one implicit node argument. This node-argument needs not be mentioned in the Parameter array of the constructor.

Since:

MMBase-1.8

Version:

$Id: NodeFunction.java,v 1.21 2006/03/02 17:25:13 michiel Exp $

Author:

Michiel Meeuwissen

See Also:

MMObjectBuilder.executeFunction(org.mmbase.module.core.MMObjectNode, java.lang.String, java.util.List), Node.getFunctionValue(java.lang.String, java.util.List), BeanFunction, Serialized Form

Field Summary

Fields inherited from class org.mmbase.util.functions.AbstractFunction

name, returnType

Constructor Summary

NodeFunction(String name, Parameter[] def, ReturnType returnType)

Method Summary

protected MMObjectNode	getCoreNode(MMObjectBuilder builder, Node node) Utility method to convert a Node to a a MMObjectNode.
static String	getFunctionNameAndFillArgs(String function, List args)
protected Object	getFunctionValue(MMObjectNode coreNode, Parameters parameters) Implements the function on a certain node.
protected abstract Object	getFunctionValue(Node node, Parameters parameters)
static FieldValue	getFunctionValue(Node node, String function) Utility function, for easy call of function on node by one string.
Object	getFunctionValue(Parameters parameters) To implement a NodeFunction, you must override getFunctionValue(Node, Parameters).
protected Node	getNode(Parameters parameters)
protected static Parameter[]	getNodeParameterDef(Parameter[] def)
Function	newInstance(MMObjectNode node) Returns a new instance of NodeInstanceFunction, which represents an actual Function.

Methods inherited from class org.mmbase.util.functions.AbstractFunction

compareTo, createParameters, equals, getDescription, getFunctionValueWithList, getName, getParameterDefinition, getReturnType, hashCode, setDescription, setParameterDefinition, setReturnType, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

NodeFunction

public NodeFunction(String name,
                    Parameter[] def,
                    ReturnType returnType)

Method Detail

getFunctionValue

public static FieldValue getFunctionValue(Node node,
                                          String function)

Utility function, for easy call of function on node by one string.

getFunctionNameAndFillArgs

public static String getFunctionNameAndFillArgs(String function,
                                                List args)

getNodeParameterDef

protected static Parameter[] getNodeParameterDef(Parameter[] def)

newInstance

public final Function newInstance(MMObjectNode node)

Returns a new instance of NodeInstanceFunction, which represents an actual Function.

getFunctionValue

protected final Object getFunctionValue(MMObjectNode coreNode,
                                        Parameters parameters)

Implements the function on a certain node. Override this method or it's bridge counter-part getFunctionValue(org.mmbase.bridge.Node, Parameters). Overriding the bridge version has two advantages. It's easier, and mmbase security will be honoured. That last thing is of course not necesary if you are not going to use other nodes. XXX: made final because it does not work well if you don't implement a bridge version

getCoreNode

protected final MMObjectNode getCoreNode(MMObjectBuilder builder,
                                         Node node)

Utility method to convert a Node to a a MMObjectNode.

getFunctionValue

protected abstract Object getFunctionValue(Node node,
                                           Parameters parameters)

getNode

protected Node getNode(Parameters parameters)

getFunctionValue

public Object getFunctionValue(Parameters parameters)

To implement a NodeFunction, you must override getFunctionValue(Node, Parameters). This one can be overriden if the same function must also be a builder function.

Specified by:

getFunctionValue in interface Function

Specified by:

getFunctionValue in class AbstractFunction

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 AbstractFunction.getReturnType()

See Also:

AbstractFunction.createParameters()