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.IRequestCycle;
018    import org.apache.tapestry.engine.ExternalServiceParameter;
019    import org.apache.tapestry.engine.IEngineService;
020    import org.apache.tapestry.engine.ILink;
021    
022    /**
023     * A component for creating a link to {@link org.apache.tapestry.IExternalPage}using
024     * the {@link org.apache.tapestry.engine.ExternalService}. [ <a
025     * href="../../../../../ComponentReference/ExternalLink.html">Component
026     * Reference </a>]
027     * 
028     * @see org.apache.tapestry.IExternalPage
029     * @see org.apache.tapestry.engine.ExternalService
030     * @author Malcolm Edgar
031     */
032    
033    public abstract class ExternalLink extends AbstractLinkComponent
034    {
035    
036        public abstract IEngineService getExternalService();
037    
038        public ILink getLink(IRequestCycle cycle)
039        {
040            Object[] serviceParameters = DirectLink
041                    .constructServiceParameters(getParameters());
042    
043            ExternalServiceParameter esp = new ExternalServiceParameter(
044                    getTargetPage(), serviceParameters);
045    
046            return getExternalService().getLink(false, esp);
047        }
048    
049        public abstract Object getParameters();
050    
051        public abstract String getTargetPage();
052    }