    001    //$HeadURL: https://svn.wald.intevation.org/svn/deegree/base/branches/2.4_testing/src/org/deegree/model/filterencoding/PropertyIsNullOperation.java $
    002    /*----------------------------------------------------------------------------
    003     This file is part of deegree, http://deegree.org/
    004     Copyright (C) 2001-2009 by:
    005       Department of Geography, University of Bonn
    006     and
    007       lat/lon GmbH
    008
    009     This library is free software; you can redistribute it and/or modify it under
    010     the terms of the GNU Lesser General Public License as published by the Free
    011     Software Foundation; either version 2.1 of the License, or (at your option)
    012     any later version.
    013     This library is distributed in the hope that it will be useful, but WITHOUT
    014     ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
    015     FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
    016     details.
    017     You should have received a copy of the GNU Lesser General Public License
    018     along with this library; if not, write to the Free Software Foundation, Inc.,
    019     59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
    020
    021     Contact information:
    022
    023     lat/lon GmbH
    024     Aennchenstr. 19, 53177 Bonn
    025     Germany
    026     http://lat-lon.de/
    027
    028     Department of Geography, University of Bonn
    029     Prof. Dr. Klaus Greve
    030     Postfach 1147, 53001 Bonn
    031     Germany
    032     http://www.geographie.uni-bonn.de/deegree/
    033
    034     e-mail: info@deegree.org
    035    ----------------------------------------------------------------------------*/
    036    package org.deegree.model.filterencoding;
    037
    038    import org.deegree.framework.xml.ElementList;
    039    import org.deegree.framework.xml.XMLParsingException;
    040    import org.deegree.framework.xml.XMLTools;
    041    import org.deegree.model.feature.Feature;
    042    import org.deegree.ogcbase.CommonNamespaces;
    043    import org.deegree.ogcbase.OGCDocument;
    044    import org.deegree.ogcbase.PropertyPath;
    045    import org.w3c.dom.Element;
    046    import org.w3c.dom.Text;
    047
    048    /**
    049     * Encapsulates the information of a &lt;PropertyIsNull&gt;-element (as defined in Filter DTD). The DTD defines the
    050     * properties type to be tested as PropertyName or Literal.
    051     *
    052     * @author <a href="mailto:schneider@lat-lon.de">Markus Schneider</a>
    053     * @author last edited by: $Author: mschneider $
    054     *
    055     * @version $Revision: 18195 $, $Date: 2009-06-18 17:55:39 +0200 (Do, 18. Jun 2009) $
    056     */
    057    public class PropertyIsNullOperation extends ComparisonOperation {
    058
    059        private PropertyName propertyName;
    060
    061        /**
    062         * @param propertyName
    063         *            to check for
    064         */
    065        public PropertyIsNullOperation( PropertyName propertyName ) {
    066            super( OperationDefines.PROPERTYISNULL );
    067            this.propertyName = propertyName;
    068        }
    069
    070        /**
    071         * @return the property name
    072         */
    073        public PropertyName getPropertyName() {
    074            return this.propertyName;
    075        }
    076
    077        /**
    078         * Given a DOM-fragment, a corresponding Operation-object is built. This method recursively calls other buildFromDOM
    079         * () - methods to validate the structure of the DOM-fragment.
    080         *
    081         * @param element
    082         *            to build the bean from
    083         * @return a Bean of the DOM
    084         *
    085         * @throws FilterConstructionException
    086         *             if the structure of the DOM-fragment is invalid
    087         * @deprecated use the 1.0.0 filter encoding aware method instead.
    088         */
    089        @Deprecated
    090        public static Operation buildFromDOM( Element element )
    091                                throws FilterConstructionException {
    092            return buildFromDOM( element, false );
    093        }
    094
    095        /**
    096         * Given a DOM-fragment, a corresponding Operation-object is built. This method recursively calls other buildFromDOM
    097         * () - methods to validate the structure of the DOM-fragment.
    098         *
    099         * @param element
    100         *            to build the bean from
    101         * @param useVersion_1_0_0
    102         *            if the filterencoding 1.0.0 should be used.
    103         * @return a Bean of the DOM
    104         *
    105         * @throws FilterConstructionException
    106         *             if the structure of the DOM-fragment is invalid
    107         */
    108        public static Operation buildFromDOM( Element element, boolean useVersion_1_0_0 )
    109                                throws FilterConstructionException {
    110
    111            // check if root element's name equals 'PropertyIsNull'
    112            if ( !element.getLocalName().equals( "PropertyIsNull" ) )
    113                throw new FilterConstructionException( "Name of element does not equal 'PropertyIsNull'!" );
    114
    115            ElementList children = XMLTools.getChildElements( element );
    116            if ( children.getLength() != 1 )
    117                throw new FilterConstructionException( "'PropertyIsNull' requires exactly 1 element!" );
    118
    119            Element child = children.item( 0 );
    120            PropertyName propertyName = null;
    121
    122            switch ( ExpressionDefines.getIdByName( child.getLocalName() ) ) {
    123            case ExpressionDefines.PROPERTYNAME: {
    124                propertyName = (PropertyName) PropertyName.buildFromDOM( child );
    125                break;
    126            }
    127            case ExpressionDefines.LITERAL: {
    128                if ( useVersion_1_0_0 ) {
    129
    130                    try {
    131                        Text node = (Text) XMLTools.getRequiredNode( child, "text()",
    132                                                                     CommonNamespaces.getNamespaceContext() );
    133                        PropertyPath propertyPath = OGCDocument.parsePropertyPath( node );
    134                        propertyName = new PropertyName( propertyPath );
    135                    } catch ( XMLParsingException e ) {
    136                        throw new FilterConstructionException(
    137                                                               "The literal "
    138                                                                                       + child.getTextContent()
    139                                                                                       + " in the PropertyIsNull operation Element could not be transformed to a 'PropertyName'!" );
    140                    }
    141                    break;
    142                }
    143                // slip through if useVersion_1_0_0 is false
    144            }
    145            default: {
    146                throw new FilterConstructionException(
    147                                                       "PropertyIsNull operation Element does not contain a 'PropertyName'!" );
    148            }
    149            }
    150
    151            return new PropertyIsNullOperation( propertyName );
    152        }
    153
    154        public StringBuffer toXML() {
    155            StringBuffer sb = new StringBuffer( 500 );
    156            sb.append( "<ogc:" ).append( getOperatorName() ).append( ">" );
    157            sb.append( propertyName.toXML() );
    158            sb.append( "</ogc:" ).append( getOperatorName() ).append( ">" );
    159            return sb;
    160        }
    161
    162        public StringBuffer to100XML() {
    163            return toXML();
    164        }
    165
    166        public StringBuffer to110XML() {
    167            return toXML();
    168        }
    169
    170        /**
    171         * Calculates the <tt>PropertyIsNull</tt> -Operation's logical value based on the certain property values of the
    172         * given <tt>Feature</tt>.
    173         *
    174         * @param feature
    175         *            that determines the property values
    176         * @return true, if the <tt>PropertyIsNull</tt> -Operation evaluates to true, else false
    177         * @throws FilterEvaluationException
    178         *             if the evaluation fails
    179         */
    180        public boolean evaluate( Feature feature )
    181                                throws FilterEvaluationException {
    182            Object value = propertyName.evaluate( feature );
    183            if ( value == null )
    184                return true;
    185            return false;
    186        }
    187    }