Application: gvSIG desktop

package org.gvsig.fmap.dal.store.h2.expressionbuilderformatter;

import java.text.MessageFormat;

import java.util.List;

import org.apache.commons.lang3.StringUtils;

import org.apache.commons.lang3.tuple.Pair;

import org.gvsig.expressionevaluator.Code.Constant;

import org.gvsig.expressionevaluator.ExpressionBuilder.Function;

import static org.gvsig.expressionevaluator.ExpressionBuilder.OPERATOR_IS;

import org.gvsig.expressionevaluator.ExpressionBuilder.Value;

import org.gvsig.expressionevaluator.Formatter;

import org.gvsig.fmap.dal.SQLBuilder;

/**

 *

 * @author jjdelcerro

 */

class IsNull implements Formatter<Value> {

    private final Formatter<Value> formatter;

    private final SQLBuilder builder;

    public IsNull(SQLBuilder builder, Formatter<Value> formatter) {

        this.builder = builder;

        this.formatter = formatter;

    }

    @Override

    public boolean canApply(Value value) {

        if (value instanceof Function) {

            if( StringUtils.equalsIgnoreCase(OPERATOR_IS, ((Function) value).name()) ) {

                List<Pair<String,Value>> parameters = ((Function) value).parameters();

                Value p2 = parameters.get(1).getValue();

                if( p2 instanceof Constant && ((Constant)p2).value()==null ) {

                    return true;

                }

            }

        }

        return false;

    }

    @Override

    public String format(Value function) {

        List<Pair<String,Value>> parameters = ((Function) function).parameters();

        String p1 = parameters.get(0).getValue().toString(formatter);

        String r = MessageFormat.format("( ({0}) IS NULL )", p1);

        return r;

    }

}