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1
27 package org.htmlparser.filters;
28
29 import java.util.regex.Matcher  ;
30 import java.util.regex.Pattern ;
31
32 import org.htmlparser.Node;
33 import org.htmlparser.NodeFilter;
34 import org.htmlparser.Tag;
35 import org.htmlparser.util.NodeList;
36
37
44 public class CssSelectorNodeFilter implements NodeFilter
45 {
46 private static Pattern tokens =
47 Pattern.compile("("
48 + "/\\*.*?\\*/" + ") | ("
50 + " \".*?[^\"]\"" + " | \'.*?[^\']\'" + " | \"\" | \'\' " + ") | ("
54 + " [\\~\\*\\$\\^]? = " + ") | ("
56 + " [a-zA-Z_\\*](?:[a-zA-Z0-9_-]|\\\\.)* " + ") | \\s*("
58 + " [+>~\\s] " + ")\\s* | ("
60 + " [\\.\\[\\]\\#\\:)(] " + ") | ("
62 + " [\\,] " + ") | ( . )" ,
65 Pattern.CASE_INSENSITIVE
66 |Pattern.DOTALL
67 |Pattern.COMMENTS);
68
69 private static final int COMMENT = 1, QUOTEDSTRING = 2, RELATION = 3,
70 NAME = 4, COMBINATOR = 5, DELIM = 6, COMMA = 7;
71
72 private NodeFilter therule;
73
74 public CssSelectorNodeFilter(String selector)
75 {
76 m = tokens.matcher(selector);
77 if (nextToken())
78 therule = parse();
79 }
80
81 public boolean accept(Node n)
82 {
83 return therule.accept(n);
84 }
85
86 private Matcher m = null;
87 private int tokentype = 0;
88 private String token = null;
89
90 private boolean nextToken()
91 {
92 if (m != null && m.find())
93 for (int i = 1; i < m.groupCount(); i++)
94 if (m.group(i) != null)
95 {
96 tokentype = i;
97 token = m.group(i);
98 return true;
99 }
100 tokentype = 0;
101 token = null;
102 return false;
103 }
104
105 private NodeFilter parse()
106 {
107 NodeFilter n = null;
108 do
109 {
110 switch (tokentype)
111 {
112 case COMMENT:
113 case NAME:
114 case DELIM:
115 if (n == null)
116 n = parseSimple();
117 else
118 n = new AndFilter(n, parseSimple());
119 break;
120 case COMBINATOR:
121 switch (token.charAt(0))
122 {
123 case '+':
124 n = new AdjacentFilter(n);
125 break;
126 case '>':
127 n = new HasParentFilter(n);
128 break;
129 default: n = new HasAncestorFilter(n);
131 }
132 nextToken();
133 break;
134 case COMMA:
135 n = new OrFilter(n, parse());
136 nextToken();
137 break;
138 }
139 }
140 while (token != null);
141 return n;
142 }
143
144 private NodeFilter parseSimple()
145 {
146 boolean done = false;
147 NodeFilter n = null;
148
149 if (token != null)
150 do
151 {
152 switch (tokentype)
153 {
154 case COMMENT:
155 nextToken();
156 break;
157 case NAME:
158 if ("*".equals(token))
159 n = new YesFilter();
160 else if (n == null)
161 n = new TagNameFilter(unescape(token));
162 else
163 n = new AndFilter(n, new TagNameFilter(unescape(token)));
164 nextToken();
165 break;
166 case DELIM:
167 switch (token.charAt(0))
168 {
169 case '.':
170 nextToken();
171 if (tokentype != NAME)
172 throw new IllegalArgumentException ("Syntax error at " + token);
173 if (n == null)
174 n = new HasAttributeFilter("class", unescape(token));
175 else
176 n
177 = new AndFilter(n, new HasAttributeFilter("class", unescape(token)));
178 break;
179 case '#':
180 nextToken();
181 if (tokentype != NAME)
182 throw new IllegalArgumentException ("Syntax error at " + token);
183 if (n == null)
184 n = new HasAttributeFilter("id", unescape(token));
185 else
186 n = new AndFilter(n, new HasAttributeFilter("id", unescape(token)));
187 break;
188 case ':':
189 nextToken();
190 if (n == null)
191 n = parsePseudoClass();
192 else
193 n = new AndFilter(n, parsePseudoClass());
194 break;
195 case '[':
196 nextToken();
197 if (n == null)
198 n = parseAttributeExp();
199 else
200 n = new AndFilter(n, parseAttributeExp());
201 break;
202 }
203 nextToken();
204 break;
205 default:
206 done = true;
207 }
208 }
209 while (!done && token != null);
210 return n;
211 }
212
213 private NodeFilter parsePseudoClass()
214 {
215 throw new IllegalArgumentException ("pseudoclasses not implemented yet");
216 }
217
218 private NodeFilter parseAttributeExp()
219 {
220 NodeFilter n = null;
221 if (tokentype == NAME)
222 {
223 String attrib = token;
224 nextToken();
225 if ("]".equals(token))
226 n = new HasAttributeFilter(unescape(attrib));
227 else if (tokentype == RELATION)
228 {
229 String val = null, rel = token;
230 nextToken();
231 if (tokentype == QUOTEDSTRING)
232 val = unescape(token.substring(1, token.length() - 1));
233 else if (tokentype == NAME)
234 val = unescape(token);
235 if ("~=".equals(rel) && val != null)
236 n = new AttribMatchFilter(unescape(attrib),
237 "\\b"
238 + val.replaceAll("([^a-zA-Z0-9])", "\\\\$1")
239 + "\\b");
240 else if ("=".equals(rel) && val != null)
241 n = new HasAttributeFilter(attrib, val);
242 }
243 }
244 if (n == null)
245 throw new IllegalArgumentException ("Syntax error at " + token + tokentype);
246
247 nextToken();
248 return n;
249 }
250
251 public static String unescape(String escaped)
252 {
253 StringBuffer result = new StringBuffer (escaped.length());
254 Matcher m = Pattern.compile("\\\\(?:([a-fA-F0-9]{2,6})|(.))").matcher(
255 escaped);
256 while (m.find())
257 {
258 if (m.group(1) != null)
259 m.appendReplacement(result,
260 String.valueOf((char)Integer.parseInt(m.group(1), 16)));
261 else if (m.group(2) != null)
262 m.appendReplacement(result, m.group(2));
263 }
264 m.appendTail(result);
265
266 return result.toString();
267 }
268
269 private static class HasAncestorFilter implements NodeFilter
270 {
271 private NodeFilter atest;
272
273 public HasAncestorFilter(NodeFilter n)
274 {
275 atest = n;
276 }
277
278 public boolean accept(Node n)
279 {
280 while (n != null)
281 {
282 n = n.getParent();
283 if (atest.accept(n))
284 return true;
285 }
286 return false;
287 }
288 }
289
290 private static class AdjacentFilter implements NodeFilter
291 {
292 private NodeFilter sibtest;
293
294 public AdjacentFilter(NodeFilter n)
295 {
296 sibtest = n;
297 }
298
299 public boolean accept(Node n)
300 {
301 if (n.getParent() != null)
302 {
303 NodeList l = n.getParent().getChildren();
304 for (int i = 0; i < l.size(); i++)
305 if (l.elementAt(i) == n && i > 0)
306 return (sibtest.accept(l.elementAt(i - 1)));
307 }
308 return false;
309 }
310 }
311
312 private static class YesFilter implements NodeFilter
313 {
314 public boolean accept(Node n)
315 {return true;}
316 }
317
318 private static class AttribMatchFilter implements NodeFilter
319 {
320 private Pattern rel;
321 private String attrib;
322
323 public AttribMatchFilter(String attrib, String regex)
324 {
325 rel = Pattern.compile(regex);
326 this.attrib = attrib;
327 }
328
329 public boolean accept(Node node)
330 {
331 if (node instanceof Tag && ((Tag)node).getAttribute(attrib) != null)
332 if (rel != null
333 && !rel.matcher(((Tag)node).getAttribute(attrib)).find())
334 return false;
335 else
336 return true;
337 else
338 return false;
339 }
340 }
341 }
342 |
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