001    /*
002     * Copyright 2005 Stephen J. McConnell
003     *
004     * Licensed  under the  Apache License,  Version 2.0  (the "License");
005     * you may not use  this file  except in  compliance with the License.
006     * You may obtain a copy of the License at
007     *
008     *   http://www.apache.org/licenses/LICENSE-2.0
009     *
010     * Unless required by applicable law or agreed to in writing, software
011     * distributed  under the  License is distributed on an "AS IS" BASIS,
012     * WITHOUT  WARRANTIES OR CONDITIONS  OF ANY KIND, either  express  or
013     * implied.
014     *
015     * See the License for the specific language governing permissions and
016     * limitations under the License.
017     */
018    
019    package net.dpml.tools.tasks;
020    
021    import net.dpml.library.Resource;
022    import net.dpml.library.Feature;
023    import net.dpml.library.Type;
024    
025    import org.apache.tools.ant.BuildException;
026    import org.apache.tools.ant.Project;
027    
028    /**
029     * Locate a named feature of the a project or resource.
030     *
031     * @author <a href="http://www.dpml.net">Digital Product Meta Library</a>
032     * @version 1.2.0
033     */
034    public abstract class FeatureTask extends ResourceTask
035    {
036        private String m_feature;
037        private String m_type; // optional - used to select type when resolving uris
038        private boolean m_alias = false; // used when resolving uris
039    
040       /**
041        * Set filename resolution switch. If true the filename feature will
042        * return an alias path.
043        *
044        * @param flag the alias switch
045        */
046        public void setAlias( final boolean flag )
047        {
048            m_alias = flag;
049        }
050    
051       /**
052        * Set the name of the feature.
053        * @param feature the feature name
054        */
055        public void setFeature( final String feature )
056        {
057            m_feature = feature;
058        }
059    
060       /**
061        * Optionaly set the resource type that the feature is related to.
062        * @param type the resource type
063        */
064        public void setType( final String type )
065        {
066            m_type = type;
067        }
068    
069       /**
070        * Return the assigned feature name.
071        * @return the feature name
072        */
073        protected String getFeature()
074        {
075            return m_feature;
076        }
077    
078       /**
079        * Resolve the feature value.
080        * @return the feature value
081        */
082        protected String resolve()
083        {
084            if( null == m_feature )
085            {
086                final String error = "Missing 'feature' attribute.";
087                throw new BuildException( error );
088            }
089            else
090            {
091                log( "Processing feature: " + m_feature, Project.MSG_VERBOSE );
092            }
093            
094            Resource resource = getResource();
095            Feature feature = Feature.parse( m_feature );
096            if( null == m_type )
097            {
098                return Feature.resolve( resource, feature );
099            }
100            else
101            {
102                Type type = resource.getType( m_type );
103                return Feature.resolve( resource, feature, type, m_alias );
104            }
105        }
106    }