1 /*
   2  * Copyright (c) 2016, 2020, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package jdk.javadoc.internal.doclets.formats.html;
  27 
  28 import java.util.Collections;
  29 
  30 import jdk.javadoc.internal.doclets.formats.html.markup.Head;
  31 import jdk.javadoc.internal.doclets.formats.html.markup.ContentBuilder;
  32 import jdk.javadoc.internal.doclets.formats.html.markup.HtmlAttr;
  33 import jdk.javadoc.internal.doclets.formats.html.markup.HtmlDocument;
  34 import jdk.javadoc.internal.doclets.formats.html.markup.HtmlTag;
  35 import jdk.javadoc.internal.doclets.formats.html.markup.HtmlTree;
  36 import jdk.javadoc.internal.doclets.formats.html.markup.Script;
  37 import jdk.javadoc.internal.doclets.formats.html.markup.StringContent;
  38 import jdk.javadoc.internal.doclets.toolkit.Content;
  39 import jdk.javadoc.internal.doclets.toolkit.util.DocFile;
  40 import jdk.javadoc.internal.doclets.toolkit.util.DocFileIOException;
  41 import jdk.javadoc.internal.doclets.toolkit.util.DocPath;
  42 import jdk.javadoc.internal.doclets.toolkit.util.DocPaths;
  43 
  44 /**
  45  * Writes a file that tries to redirect to an alternate page.
  46  * The redirect uses JavaScript, if enabled, falling back on
  47  * {@code <meta http-equiv=refresh content="0,<uri>">}.
  48  * If neither are supported/enabled in a browser, the page displays the
  49  * standard "JavaScript not enabled" message, and a link to the alternate page.
  50  */
  51 public class IndexRedirectWriter extends HtmlDocletWriter {
  52 
  53     public static void generate(HtmlConfiguration configuration)
  54             throws DocFileIOException {
  55         generate(configuration, DocPaths.INDEX, configuration.topFile);
  56     }
  57 
  58     public static void generate(HtmlConfiguration configuration, DocPath fileName, DocPath target)
  59             throws DocFileIOException {
  60         IndexRedirectWriter indexRedirect = new IndexRedirectWriter(configuration, fileName, target);
  61         indexRedirect.generateIndexFile();
  62     }
  63 
  64     private DocPath target;
  65 
  66     private IndexRedirectWriter(HtmlConfiguration configuration, DocPath filename, DocPath target) {
  67         super(configuration, filename);
  68         this.target = target;
  69     }
  70 
  71     /**
  72      * Generate an index file that redirects to an alternate file.
  73      * @throws DocFileIOException if there is a problem generating the file
  74      */
  75     private void generateIndexFile() throws DocFileIOException {
  76         Content htmlComment = contents.newPage;
  77         Head head = new Head(path, configuration.docletVersion, configuration.startTime)
  78                 .setTimestamp(!configuration.notimestamp)
  79                 .setDescription("index redirect")
  80                 .setGenerator(getGenerator(getClass()))
  81                 .setStylesheets(configuration.getMainStylesheet(), Collections.emptyList()) // avoid reference to default stylesheet
  82                 .addDefaultScript(false);
  83 
  84         String title = (configuration.windowtitle.length() > 0)
  85                 ? configuration.windowtitle
  86                 : resources.getText("doclet.Generated_Docs_Untitled");
  87 
  88         head.setTitle(title)
  89                 .setCharset(configuration.charset)
  90                 .setCanonicalLink(target);
  91 
  92         String targetPath = target.getPath();
  93         Script script = new Script("window.location.replace(")
  94                 .appendStringLiteral(targetPath, '\'')
  95                 .append(")");
  96         HtmlTree metaRefresh = new HtmlTree(HtmlTag.META)
  97                 .put(HtmlAttr.HTTP_EQUIV, "Refresh")
  98                 .put(HtmlAttr.CONTENT, "0;" + targetPath);
  99         head.addContent(script.asContent(), HtmlTree.NOSCRIPT(metaRefresh));
 100 
 101         ContentBuilder bodyContent = new ContentBuilder();
 102         bodyContent.add(HtmlTree.NOSCRIPT(
 103                 HtmlTree.P(contents.getContent("doclet.No_Script_Message"))));
 104 
 105         bodyContent.add(HtmlTree.P(HtmlTree.A(targetPath, new StringContent(targetPath))));
 106 
 107         Content body = new HtmlTree(HtmlTag.BODY)
 108                 .put(HtmlAttr.CLASS, "index-redirect");
 109         HtmlTree main = HtmlTree.MAIN(bodyContent);
 110         body.add(main);
 111 
 112         Content htmlTree = HtmlTree.HTML(configuration.getLocale().getLanguage(), head.toContent(), body);
 113         HtmlDocument htmlDocument = new HtmlDocument(htmlComment, htmlTree);
 114         htmlDocument.write(DocFile.createFileForOutput(configuration, path));
 115     }
 116 }