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1 package com.opensymphony.module.sitemesh.html.tokenizer;
2
3 import com.opensymphony.module.sitemesh.html.Tag;
4 import com.opensymphony.module.sitemesh.html.Text;
5
6 /**
7 * Handler passed to {@link TagTokenizer} that will receive callbacks as 'tags' and 'text' are encountered.
8 *
9 * @author Joe Walnes
10 * @see TagTokenizer
11 */
12 public interface TokenHandler {
13
14 /**
15 * Before attempting to parse a tag, the tokenizer will ask the handler whether the tag should be processed - avoiding
16 * additional tag parsing makes the tokenizer quicker.
17 * <p/>
18 * If true is returned, the tokenizer will fully parse the tag and pass it into the {@link #tag(com.opensymphony.module.sitemesh.html.Tag)} method.
19 * If false is returned, the tokenizer will not try to parse the tag and pass it to the #{@link #text(com.opensymphony.module.sitemesh.html.Text)} method,
20 * untouched.
21 */
22 boolean shouldProcessTag(String name);
23
24 /**
25 * Called when tokenizer encounters an HTML tag (open, close or empty).
26 *
27 * The Tag instance passed in should not be kept beyond the scope of this method as the tokenizer will attempt
28 * to reuse it.
29 */
30 void tag(Tag tag);
31
32 /**
33 * Called when tokenizer encounters anything other than a well-formed HTML tag.
34 *
35 * The Text object is used instead of a String to allow the String to be lazy-loaded.
36 *
37 * The Text instance passed in should not be kept beyond the scope of this method as the tokenizer will attempt
38 * to reuse it.
39 */
40 void text(Text text);
41
42 /**
43 * Called when tokenizer encounters something it cannot correctly parse. Typically the parsing will continue and the
44 * unparseable will be treated as a plain text block, however this callback provides indication of this.
45 *
46 * @param message Error message
47 * @param line Line number in input that error occured
48 * @param column Column number in input that error occured
49 */
50 void warning(String message, int line, int column);
51
52 }