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.engine; 016 017 /** 018 * Encapsulates the logic for encoding and decoding service requests. 019 * 020 * @author Howard M. Lewis Ship 021 * @since 4.0 022 */ 023 public interface ServiceEncoder 024 { 025 /** 026 * Invoked by the {@link org.apache.tapestry.services.LinkFactory} to encode the request. 027 * Encoding is the process of modifying the encoding object to represent the same data in a 028 * different format; the canoncial example is to replace the 029 * {@link org.apache.tapestry.services.ServiceConstants#PAGE}and 030 * {@link org.apache.tapestry.services.ServiceConstants#SERVICE}query parameters with a servlet 031 * path (i.e., "/Home.html", if the ".html" extension is mapped to the page service). 032 * <p> 033 * The {@link org.apache.tapestry.services.LinkFactory} iterates over a collection of 034 * encoders, stopping once the ServiceRequestEncoding is modified in any way. 035 */ 036 037 public void encode(ServiceEncoding encoding); 038 039 /** 040 * Invoked to decode a request. The encoder is responsible for recognizing a request it may have 041 * encoded, and for restoring any query parameters is may have removed. 042 */ 043 044 public void decode(ServiceEncoding encoding); 045 }