1 package org.apache.maven.doxia.module.apt;
2
3 /*
4 * Licensed to the Apache Software Foundation (ASF) under one
5 * or more contributor license agreements. See the NOTICE file
6 * distributed with this work for additional information
7 * regarding copyright ownership. The ASF licenses this file
8 * to you under the Apache License, Version 2.0 (the
9 * "License"); you may not use this file except in compliance
10 * with the License. You may obtain a copy of the License at
11 *
12 * http://www.apache.org/licenses/LICENSE-2.0
13 *
14 * Unless required by applicable law or agreed to in writing,
15 * software distributed under the License is distributed on an
16 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17 * KIND, either express or implied. See the License for the
18 * specific language governing permissions and limitations
19 * under the License.
20 */
21
22 import org.apache.maven.doxia.util.DoxiaUtils;
23
24 /**
25 * A collection of utility methods for dealing with APT documents.
26 *
27 * @author ltheussl
28 * @since 1.1
29 */
30 public class AptUtils
31 {
32
33 /**
34 * Replace all characters in a text.
35 *
36 * <pre>
37 * AptTools.encodeFragment( null ) = null
38 * AptTools.encodeFragment( "" ) = ""
39 * AptTools.encodeFragment( "http://www.google.com" ) = "httpwwwgooglecom"
40 * </pre>
41 *
42 * @param text the String to check, may be null.
43 * @return the text with only letter and digit, null if null String input.
44 * @deprecated This method was used for the original apt format, which
45 * removed all non alphanumeric characters from anchors.
46 * Use {@link #encodeAnchor(String)} instead.
47 */
48 public static String encodeFragment( String text )
49 {
50 if ( text == null )
51 {
52 return null;
53 }
54
55 return linkToKey( text );
56 }
57
58 /**
59 * Checks if the given string corresponds to an external URI,
60 * ie is not a link within the same document nor a link to another
61 * document within the same site. This forwards to
62 * {@link org.apache.maven.doxia.util.DoxiaUtils#isExternalLink(String)}.
63 *
64 * @param link The link to check.
65 * @return True if DoxiaUtils.isExternalLink(link) returns true.
66 * @see org.apache.maven.doxia.util.DoxiaUtils#isExternalLink(String)
67 * @see #isInternalLink(String)
68 * @see #isLocalLink(String)
69 */
70 public static boolean isExternalLink( String link )
71 {
72 return DoxiaUtils.isExternalLink( link );
73 }
74
75 /**
76 * Checks if the given string corresponds to an internal link,
77 * ie it is a link to an anchor within the same document.
78 *
79 * @param link The link to check.
80 * @return True if link is neither an {@link #isExternalLink(String) external}
81 * nor a {@link #isLocalLink(String) local} link.
82 * @see org.apache.maven.doxia.util.DoxiaUtils#isInternalLink(String)
83 * @see #isExternalLink(String)
84 * @see #isLocalLink(String)
85 */
86 public static boolean isInternalLink( String link )
87 {
88 return ( !isExternalLink( link ) && !isLocalLink( link ) );
89 }
90
91 /**
92 * Checks if the given string corresponds to a relative link to another document
93 * within the same site.
94 *
95 * @param link The link to check.
96 * @return True if the link starts with either "/", "./" or "../".
97 * @see org.apache.maven.doxia.util.DoxiaUtils#isLocalLink(String)
98 * @see #isExternalLink(String)
99 * @see #isInternalLink(String)
100 */
101 public static boolean isLocalLink( String link )
102 {
103 return ( link.startsWith( "/" ) || link.startsWith( "./" ) || link.startsWith( "../" ) );
104 }
105
106 /**
107 * Transforms the given text such that it can be used as a link.
108 * All non-LetterOrDigit characters are removed and the remaining
109 * characters are transformed to lower-case.
110 *
111 * @param text The text to transform.
112 * @return The text with all non-LetterOrDigit characters removed.
113 * @deprecated This method was used for the original apt format, which
114 * removed all non alphanumeric characters from anchors.
115 * Use {@link #encodeAnchor(String)} instead.
116 */
117 public static String linkToKey( String text )
118 {
119 int length = text.length();
120 StringBuilder buffer = new StringBuilder( length );
121
122 for ( int i = 0; i < length; ++i )
123 {
124 char c = text.charAt( i );
125 if ( Character.isLetterOrDigit( c ) )
126 {
127 buffer.append( Character.toLowerCase( c ) );
128 }
129 }
130
131 return buffer.toString();
132 }
133
134 /**
135 * Construct a valid anchor. This is a simplified version of
136 * {@link org.apache.maven.doxia.util.DoxiaUtils#encodeId(String)}
137 * to ensure the anchor is a valid Doxia id.
138 * The procedure is identical to the one in
139 * {@link org.apache.maven.doxia.util.HtmlTools#encodeId(String)}:
140 *
141 * <ol>
142 * <li> Trim the id</li>
143 * <li> If the first character is not a letter, prepend the letter 'a'</li>
144 * <li> Any space is replaced with an underscore '_'</li>
145 * <li> Remove any non alphanumeric characters except ':', '_', '.', '-'.</li>
146 * </ol>
147 *
148 * @param id The id to be encoded.
149 * @return The trimmed and encoded id, or null if id is null.
150 */
151 public static String encodeAnchor( String id )
152 {
153 if ( id == null )
154 {
155 return null;
156 }
157
158 id = id.trim();
159
160 int length = id.length();
161 StringBuilder buffer = new StringBuilder( length );
162
163 for ( int i = 0; i < length; ++i )
164 {
165 char c = id.charAt( i );
166
167 if ( ( i == 0 ) && ( !Character.isLetter( c ) ) )
168 {
169 buffer.append( 'a' );
170 }
171
172 if ( c == ' ' )
173 {
174 buffer.append( '_' );
175 }
176 else if ( ( Character.isLetterOrDigit( c ) ) || ( c == '-' ) || ( c == '_' ) || ( c == ':' )
177 || ( c == '.' ) )
178 {
179 buffer.append( c );
180 }
181 }
182
183 return buffer.toString();
184 }
185
186 private AptUtils()
187 {
188 // utility class
189 }
190 }