org.deegree.model.filterencoding
Class Function

java.lang.Object
  org.deegree.model.filterencoding.Expression
      org.deegree.model.filterencoding.Function

Direct Known Subclasses:

DBFunction, FunctionNormalize, FunctionSoundex

public abstract class Function
extends Expression

Encapsulates the information of a Functionelement as defined in the Expression DTD.

Version:

$Revision: 18195 $, $Date: 2009-06-18 17:55:39 +0200 (Do, 18. Jun 2009) $

Author:

Markus Schneider, last edited by: $Author: mschneider $

Field Summary

protected List<Expression>	args The Function's arguments.
protected String	name The Function's name (as specified in it's name attribute).

Fields inherited from class org.deegree.model.filterencoding.Expression

id

Constructor Summary

protected	Function()
	Function(String name, List<Expression> args) Constructs a new Function.

Method Summary

static Expression	buildFromDOM(Element element) Given a DOM-fragment, a corresponding Expression-object is built.
abstract Object	evaluate(Feature feature) Returns the Function's value (to be used in the evaluation of a complexer Expression).
List<Expression>	getArguments() returns the arguments of the function
int	getExpressionId()
String	getName() Returns the Function's name.
void	setArguments(List<Expression> args)
void	setName(String name)
StringBuffer	toXML() Produces an indented XML representation of this object.

Methods inherited from class org.deegree.model.filterencoding.Expression

getExpressionName

Methods inherited from class java.lang.Object

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

Field Detail

name

protected String name

The Function's name (as specified in it's name attribute).

args

protected List<Expression> args

The Function's arguments.

Constructor Detail

Function

protected Function()

Function

public Function(String name,
                List<Expression> args)

Constructs a new Function.

Parameters:

name -

args -

Method Detail

setArguments

public void setArguments(List<Expression> args)

Parameters:

args -

buildFromDOM

public static Expression buildFromDOM(Element element)
                               throws FilterConstructionException

Given a DOM-fragment, a corresponding Expression-object is built. This method recursively calls other buildFromDOM () - methods to validate the structure of the DOM-fragment.

Throws:

FilterConstructionException - if the structure of the DOM-fragment is invalid

getName

public String getName()

Returns the Function's name.

Returns:

functions name

setName

public void setName(String name)

Parameters:

name -

See Also:

getName()

getArguments

public List<Expression> getArguments()

returns the arguments of the function

Returns:

arguments of the function

getExpressionId

public int getExpressionId()

Overrides:

getExpressionId in class Expression

Returns:

the expression's id.

See Also:

ExpressionDefines

evaluate

public abstract Object evaluate(Feature feature)
                         throws FilterEvaluationException

Returns the Function's value (to be used in the evaluation of a complexer Expression).

Specified by:

evaluate in class Expression

Parameters:

feature - that determines the concrete values of PropertyNames found in the expression

Returns:

the resulting value

Throws:

FilterEvaluationException - if the evaluation fails

toXML

public StringBuffer toXML()

Produces an indented XML representation of this object.

Specified by:

toXML in class Expression

Returns:

xml representation