Application: gvSIG desktop

/* gvSIG. Sistema de Informaci�n Geogr�fica de la Generalitat Valenciana

 *

 * Copyright (C) 2004 IVER T.I. and Generalitat Valenciana.

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU General Public License

 * as published by the Free Software Foundation; either version 2

 * of the License, or (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,USA.

 *

 * For more information, contact:

 *

 *  Generalitat Valenciana

 *   Conselleria d'Infraestructures i Transport

 *   Av. Blasco Ib��ez, 50

 *   46010 VALENCIA

 *   SPAIN

 *

 *      +34 963862235

 *   gvsig@gva.es

 *      www.gvsig.gva.es

 *

 *    or

 *

 *   IVER T.I. S.A

 *   Salamanca 50

 *   46005 Valencia

 *   Spain

 *

 *   +34 963163400

 *   dac@iver.es

 */

package org.gvsig.sldsupport.filterencoding;

import java.io.IOException;

import org.xmlpull.v1.XmlPullParser;

import org.xmlpull.v1.XmlPullParserException;

/**

 * Implements the main functionalities to parse a PropertyIsNull element

 * of a Filter Encoding expression<br>

 * 

 * The PropertyIsNull element encodes an operator that checks to see if the 

 * value of its content is NULL. A NULL is equivalent to no value present.

 * The value 0 is valid value and is not considered NULL.  

 * 

 * @see http://www.opengeospatial.org/standards/filter

 * @author pepe vidal salvador - jose.vidal.salvador@iver.es

 */

public class FIsNullOperator{

        protected String propName;

        protected String opExpressionStr = "";

        public void parse(XmlPullParser parser, int Tag2, String expressionType)

                        throws XmlPullParserException, IOException {

                int currentTag;

                boolean end = false;

                currentTag = Tag2;

                parser.require(XmlPullParser.START_TAG, null, FilterTags.PROPERTYISNULL);

                while (!end)

                {

                        switch(currentTag)

                        {

                        case XmlPullParser.START_TAG:

                                if (parser.getName().compareTo(

                                                FilterUtils.remNameSpace(FilterTags.PROPERTYNAME))==0) {

                                        this.propName = parser.nextText();

                                        opExpressionStr += "( ["+this.propName+"] ) ";

                                }

                                break;        

                        case XmlPullParser.END_TAG:

                                if (parser.getName().compareTo(FilterUtils.remNameSpace(FilterTags.PROPERTYISNULL)) == 0)

                                        end = true;

                                break;

                        case XmlPullParser.TEXT:

                                break;

                        }

                        if (!end)

                                currentTag = parser.next();

                }

        }

        public String getPropName() { return propName; }

        public String getOpExpressionStr() {return opExpressionStr;}

}