1 /*
2 * Licensed under the Apache License, Version 2.0 (the "License");
3 * you may not use this file except in compliance with the License.
4 * You may obtain a copy of the License at
5 *
6 * http://www.apache.org/licenses/LICENSE-2.0
7 *
8 * Unless required by applicable law or agreed to in writing, software
9 * distributed under the License is distributed on an "AS IS" BASIS,
10 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
11 * See the License for the specific language governing permissions and
12 * limitations under the License.
13 *
14 */
15 package org.esigate.parser;
16
17 import java.io.IOException;
18
19 import org.esigate.HttpErrorPage;
20
21 /**
22 * An element represents a tag inside a document.
23 *
24 * @author Francois-Xavier Bonnet
25 *
26 */
27 public interface Element {
28 /**
29 * Method called by the parser when it finds an opening tag.
30 *
31 * @param tag
32 * The tag
33 * @param ctx
34 * The parser context
35 * @return true if the body of this tag should be evaluated
36 * @throws IOException
37 * @throws HttpErrorPage
38 */
39 boolean onTagStart(String tag, ParserContext ctx) throws IOException, HttpErrorPage;
40
41 /**
42 * Method called by the parser when it finds the matching closing tag.
43 *
44 * @param tag
45 * The tag
46 * @param ctx
47 * @throws IOException
48 * @throws HttpErrorPage
49 */
50 void onTagEnd(String tag, ParserContext ctx) throws IOException, HttpErrorPage;
51
52 /**
53 * @param e
54 * @param ctx
55 * @return <code>true</code> if error has been handled by this element and it should not be propagated further.
56 */
57 boolean onError(Exception e, ParserContext ctx);
58
59 /**
60 * Method called by the parser when it finds characters between starting and closing tags.
61 *
62 * @param csq
63 * the {@link CharSequence} to append
64 * @param start
65 * the start index in the {@link CharSequence}. Allows to append only a subset of the
66 * {@link CharSequence}.
67 * @param end
68 * the end index in the {@link CharSequence}. Allows to append only a subset of the {@link CharSequence}.
69 * @throws IOException
70 */
71 void characters(CharSequence csq, int start, int end) throws IOException;
72
73 }