Application: gvSIG desktop

package org.gvsig.expressionevaluator.impl.function.programming;

import org.apache.commons.lang3.Range;

import org.gvsig.expressionevaluator.Codes;

import org.gvsig.expressionevaluator.Function;

import org.gvsig.expressionevaluator.Interpreter;

import org.gvsig.expressionevaluator.spi.AbstractFunction;

public class IFNULLFunction extends AbstractFunction {

    public IFNULLFunction() {

        super(Function.GROUP_BOOLEAN, 

                "IFNULL", 

                Range.is(3),

                "The IFNULL() function tests if a specified value is null and returns one of two values, based on whether the value is null was true or false.",

                "IFNULL( {{value}}, true, false )",

                null,

                "Object",

                true

        );

    }

    @Override

    public boolean useArgumentsInsteadObjects() {

        return true;

    }

    @Override

    public boolean allowConstantFolding() {

        return false;

    }

    @Override

    public Object call(Interpreter interpreter, Object[] args) throws Exception {

        throw new UnsupportedOperationException("Not supported yet."); 

    }

    @Override

    public Object call(Interpreter interpreter, Codes args) throws Exception {

        Object value = getObject(interpreter, args, 0);

        if( value == null ) {

            value = getObject(interpreter, args, 1);

        } else {

            value = getObject(interpreter, args, 2);

        }

        return value;

    }

}