001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.juneau.rest.vars;
018
019import static org.apache.juneau.commons.utils.FileUtils.*;
020
021import org.apache.juneau.http.response.*;
022import org.apache.juneau.rest.*;
023import org.apache.juneau.svl.*;
024
025/**
026 * File resource variable resolver
027 *
028 * <p>
029 * The format for this var is <js>"$F{path[,defaultValue]}"</js>.
030 *
031 * <p>
032 * Contents of files are retrieved from the request using {@link RestRequest#getStaticFiles()}.
033
034 * <p>
035 * Localized resources (based on the locale of the HTTP request) are supported.
036 * For example, if looking for the resource <js>"MyResource.txt"</js> for the Japanese locale, we will look for
037 * files in the following order:
038 * <ol>
039 *    <li><js>"MyResource_ja_JP.txt"</js>
040 *    <li><js>"MyResource_ja.txt"</js>
041 *    <li><js>"MyResource.txt"</js>
042 * </ol>
043 *
044 * <p>
045 * Example:
046 * <p class='bjava'>
047 *  <ja>@HtmlDocConfig</ja>(
048 *       aside=<js>"$F{resources/MyAsideMessage.html, Oops not found!}"</js>
049 *    )
050 * </p>
051 *
052 * <p>
053 * Files of type HTML, XHTML, XML, JSON, Javascript, and CSS will be stripped of comments.
054 * This allows you to place license headers in files without them being serialized to the output.
055 *
056 * <p>
057 * This variable resolver requires that a {@link RestRequest} bean be available in the session bean store.
058 *
059 * <h5 class='section'>See Also:</h5><ul>
060 *    <li class='link'><a class="doclink" href="https://juneau.apache.org/docs/topics/RestServerSvlVariables">SVL Variables</a>
061 * </ul>
062 */
063public class FileVar extends DefaultingVar {
064
065   /**
066    * The name of this variable.
067    */
068   public static final String NAME = "F";
069
070   /**
071    * Constructor.
072    */
073   public FileVar() {
074      super(NAME);
075   }
076
077   @Override /* Overridden from Var */
078   public boolean canResolve(VarResolverSession session) {
079      return session.getBean(RestRequest.class).isPresent();
080   }
081
082   @Override /* Overridden from Var */
083   public String resolve(VarResolverSession session, String key) throws Exception {
084
085      RestRequest req = session.getBean(RestRequest.class).orElseThrow(InternalServerError::new);
086
087      String s = req.getStaticFiles().getString(key, null).orElse(null);
088      if (s == null)
089         return null;
090      String subType = getFileExtension(key);
091      if ("html".equals(subType) || "xhtml".equals(subType) || "xml".equals(subType))
092         s = s.replaceAll("(?s)<!--(.*?)-->\\s*", "");
093      else if ("json".equals(subType) || "javascript".equals(subType) || "css".equals(subType))
094         s = s.replaceAll("(?s)\\/\\*(.*?)\\*\\/\\s*", "");
095      return s;
096   }
097}