1 /*
   2  * Copyright (c) 2017, 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 build.tools.taglet;
  27 
  28 import java.util.EnumSet;
  29 import java.util.List;
  30 import java.util.Set;
  31 import java.util.regex.Matcher;
  32 import java.util.regex.Pattern;
  33 import javax.lang.model.element.Element;
  34 
  35 import com.sun.source.doctree.DocTree;
  36 import com.sun.source.doctree.UnknownInlineTagTree;
  37 import jdk.javadoc.doclet.Taglet;
  38 
  39 import static com.sun.source.doctree.DocTree.Kind.*;
  40 
  41 /**
  42  * An inline tag to conveniently insert an external link.
  43  * The tag can be used as follows:
  44  * {@extLink name description}.
  45  * <p>
  46  * Using the tag as follows:
  47  * <br>
  48  * {@code Please see {@extLink Borealis a spectacular} sight.}
  49  * <br>
  50  * the taglet will produce the following html:
  51  * <br><br>
  52  * {@code Please see <cite>a spectacular</cite> sight.}
  53  * <br><br>
  54  * If the property {@code build.tools.taglet.ExtLink.LINK} is set, using
  55  * the above example, the taglet will produce the following html:
  56  * <br><br>
  57  * {@code
  58  * Please see <a href="https://www.oracle.com/pls/topic/lookup?ctx=javase9&id=Borealis">a spectacular</a> sight.
  59  * }
  60  */
  61 public class ExtLink implements Taglet {
  62 
  63     static final String TAG_NAME = "extLink";
  64 
  65     static final String URL = "https://www.oracle.com/pls/topic/lookup?ctx=javase9&id=";
  66 
  67     static final Pattern TAG_PATTERN = Pattern.compile("(\\s*)(?<name>\\w+)(\\s+)(?<desc>.*)");
  68 
  69     static final boolean LINK = Boolean.getBoolean("build.tools.taglet.ExtLink.LINK");
  70 
  71     /**
  72      * Returns the set of locations in which the tag may be used.
  73      */
  74     @Override
  75     public Set<Location> getAllowedLocations() {
  76         return EnumSet.allOf(jdk.javadoc.doclet.Taglet.Location.class);
  77     }
  78 
  79     @Override
  80     public boolean isInlineTag() {
  81         return true;
  82     }
  83 
  84     @Override
  85     public String getName() {
  86         return TAG_NAME;
  87     }
  88 
  89     @Override
  90     public String toString(List<? extends DocTree> tags, Element elem) {
  91 
  92         if (tags.isEmpty())
  93             return "";
  94 
  95         DocTree tag = tags.get(0);
  96         if (tag.getKind() != UNKNOWN_INLINE_TAG)
  97             return "";
  98 
  99         UnknownInlineTagTree uitree = (UnknownInlineTagTree) tag;
 100         if (uitree.getContent().isEmpty())
 101             return "";
 102 
 103         String tagText = uitree.getContent().get(0).toString();
 104         Matcher m = TAG_PATTERN.matcher(tagText);
 105         if (!m.find())
 106             return "";
 107 
 108         StringBuilder sb = new StringBuilder();
 109         if (LINK) {
 110             sb.append("<a href=\"")
 111               .append(URL)
 112               .append(m.group("name"))
 113               .append("\">")
 114               .append(m.group("desc"))
 115               .append("</a>");
 116         } else {
 117             sb.append("<cite>")
 118               .append(m.group("desc"))
 119               .append("</cite>");
 120         }
 121         return sb.toString();
 122     }
 123 }