001    // Copyright 2004, 2005 The Apache Software Foundation
002    //
003    // Licensed under the Apache License, Version 2.0 (the "License");
004    // you may not use this file except in compliance with the License.
005    // You may obtain a copy of the License at
006    //
007    //     http://www.apache.org/licenses/LICENSE-2.0
008    //
009    // Unless required by applicable law or agreed to in writing, software
010    // distributed under the License is distributed on an "AS IS" BASIS,
011    // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
012    // See the License for the specific language governing permissions and
013    // limitations under the License.
014    
015    package org.apache.tapestry.link;
016    
017    import org.apache.tapestry.INamespace;
018    import org.apache.tapestry.IRequestCycle;
019    import org.apache.tapestry.engine.ExternalServiceParameter;
020    import org.apache.tapestry.engine.IEngineService;
021    import org.apache.tapestry.engine.ILink;
022    
023    /**
024     * A component for creating a link to {@link org.apache.tapestry.IExternalPage}using
025     * the {@link org.apache.tapestry.engine.ExternalService}. [ <a
026     * href="../../../../../ComponentReference/ExternalLink.html">Component
027     * Reference </a>]
028     * 
029     * @see org.apache.tapestry.IExternalPage
030     * @see org.apache.tapestry.engine.ExternalService
031     * @author Malcolm Edgar
032     */
033    
034    public abstract class ExternalLink extends AbstractLinkComponent
035    {
036        public abstract IEngineService getExternalService();
037    
038        public ILink getLink(IRequestCycle cycle)
039        {
040            Object[] serviceParameters = DirectLink.constructServiceParameters(getParameters());
041            
042            INamespace namespace = getTargetNamespace();
043            
044            String targetPage = (namespace==null) ? getTargetPage() : namespace.constructQualifiedName(getTargetPage());
045    
046            ExternalServiceParameter esp = new ExternalServiceParameter(targetPage, serviceParameters);
047    
048            return getExternalService().getLink(false, esp);
049        }
050    
051        public abstract Object getParameters();
052    
053        public abstract String getTargetPage();
054        
055        public abstract INamespace getTargetNamespace();
056    }