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 import static jdk.javadoc.doclet.Taglet.Location.*;
  41 
  42 /**
  43  * An inline tag to conveniently insert an external link.
  44  * The tag can be used as follows:
  45  * {@extLink name description}, for example
  46  * <p>
  47  * {@code Please see {@extLink Borealis a spectacular} sight.}
  48  * <p>
  49  * will produce the following html
  50  * <p>
  51  * {@code
  52  * Please see <a href="https://www.oracle.com/pls/topic/lookup?ctx=javase10&id=Borealis">a spectacular</a> sight.
  53  * }
  54  */
  55 public class ExtLink implements Taglet {
  56 
  57     static final String TAG_NAME = "extLink";
  58 
  59     static final String URL = "https://www.oracle.com/pls/topic/lookup?ctx=javase10&amp;id=";
  60 
  61     static final Pattern TAG_PATTERN = Pattern.compile("(?s)(\\s*)(?<name>\\w+)(\\s+)(?<desc>.*)$");
  62 
  63     /**
  64      * Returns the set of locations in which the tag may be used.
  65      */
  66     @Override
  67     public Set<Location> getAllowedLocations() {
  68         return EnumSet.allOf(jdk.javadoc.doclet.Taglet.Location.class);
  69     }
  70 
  71     @Override
  72     public boolean isInlineTag() {
  73         return true;
  74     }
  75 
  76     @Override
  77     public String getName() {
  78         return TAG_NAME;
  79     }
  80 
  81     @Override
  82     public String toString(List<? extends DocTree> tags, Element elem) {
  83 
  84         if (tags.isEmpty())
  85             return "";
  86 
  87         DocTree tag = tags.get(0);
  88         if (tag.getKind() != UNKNOWN_INLINE_TAG)
  89             return "";
  90 
  91         UnknownInlineTagTree uitree = (UnknownInlineTagTree) tag;
  92         if (uitree.getContent().isEmpty())
  93             return "";
  94 
  95         String tagText = uitree.getContent().get(0).toString();
  96         Matcher m = TAG_PATTERN.matcher(tagText);
  97         if (!m.find())
  98             return "";
  99 
 100         StringBuilder sb = new StringBuilder("<a href=\"");
 101         sb.append(URL)
 102           .append(m.group("name"))
 103           .append("\">")
 104           .append(m.group("desc"))
 105           .append("</a>");
 106 
 107         return sb.toString();
 108     }
 109 }