base/runtime/org.argeo.eclipse.ui.rap/src/main/java/org/argeo/eclipse/ui/specific/FileHandler.java

   1 /*
   2  * Copyright (C) 2007-2012 Mathieu Baudier
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  *         http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16 package org.argeo.eclipse.ui.specific;
  17
  18 import java.net.URL;
  19
  20 import org.apache.commons.logging.Log;
  21 import org.apache.commons.logging.LogFactory;
  22 import org.eclipse.rwt.RWT;
  23 import org.eclipse.rwt.service.IServiceHandler;
  24 import org.eclipse.rwt.service.IServiceManager;
  25 import org.eclipse.ui.PlatformUI;
  26
  27 /**
  28  * RAP SPECIFIC handler to enable the opening of a download dialog box triggered
  29  * by whatever action in the UI
  30  *
  31  * Manages the registration of the effective DownloadServiceHandler at
  32  * instantiation time.
  33  *
  34  * Manages the process of forwarding the request to the handler at runtime to
  35  * open the dialog box
  36  *
  37  */
  38 public class FileHandler {
  39         public final static String FORCED_DOWNLOAD_URL_BASE_PROPERTY = "argeo.rap.specific.forcedDownloadUrlBase";
  40
  41         private final static Log log = LogFactory.getLog(FileHandler.class);
  42
  43         public FileHandler(FileProvider provider) {
  44                 // Instantiate and register the DownloadServicHandler.
  45                 IServiceManager manager = RWT.getServiceManager();
  46                 IServiceHandler handler = new DownloadServiceHandler(provider);
  47                 manager.registerServiceHandler("downloadServiceHandler", handler);
  48         }
  49
  50         public void openFile(String fileName, String fileId) {
  51
  52                 // See RAP FAQ:
  53                 // http://wiki.eclipse.org/RAP/FAQ#How_to_provide_download_link.3F
  54                 // And forum discussion :
  55                 // http://www.eclipse.org/forums/index.php?t=msg&th=205487&start=0&S=43d85dacc88b505402420592109c7240
  56
  57                 try {
  58                         if (log.isTraceEnabled())
  59                                 log.trace("URL : " + createFullDownloadUrl(fileName, fileId));
  60
  61                         URL url = new URL(createFullDownloadUrl(fileName, fileId));
  62                         PlatformUI.getWorkbench().getBrowserSupport()
  63                                         .createBrowser("DownloadDialog").openURL(url);
  64                 } catch (Exception e) {
  65                         e.printStackTrace();
  66                 }
  67
  68                 // These lines are useless in the current use case but might be
  69                 // necessary with new browsers. Stored here for memo
  70                 // response.setContentType("application/force-download");
  71                 // response.setHeader("Content-Disposition", contentDisposition);
  72                 // response.setHeader("Content-Transfer-Encoding", "binary");
  73                 // response.setHeader("Pragma", "no-cache");
  74                 // response.setHeader("Cache-Control", "no-cache, must-revalidate");
  75         }
  76
  77         private String createFullDownloadUrl(String fileName, String fileId) {
  78                 StringBuilder url = new StringBuilder();
  79                 // in case RAP is proxied we need to specify the actual base URL
  80                 // TODO find a cleaner way
  81                 String forcedDownloadUrlBase = System
  82                                 .getProperty(FORCED_DOWNLOAD_URL_BASE_PROPERTY);
  83                 if (forcedDownloadUrlBase != null)
  84                         url.append(forcedDownloadUrlBase);
  85                 else
  86                         url.append(RWT.getRequest().getRequestURL());
  87                 url.append(createParamUrl(fileName, fileId));
  88                 return url.toString();
  89         }
  90
  91         private String createParamUrl(String filename, String fileId) {
  92                 StringBuilder url = new StringBuilder();
  93                 url.append("?");
  94                 url.append(IServiceHandler.REQUEST_PARAM);
  95                 url.append("=downloadServiceHandler");
  96                 url.append("&filename=");
  97                 url.append(filename);
  98                 url.append("&fileid=");
  99                 url.append(fileId);
 100                 String encodedURL = RWT.getResponse().encodeURL(url.toString());
 101                 return encodedURL;
 102         }
 103 }