ExternalState.java revision 56ed4167b942ec265f9cee70ac4d71d10b3835ce 
1/*
2 * Copyright (C) 2010 Google Inc.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package com.google.streamhtmlparser;
18
19import com.google.common.base.Preconditions;
20
21/**
22 * A representation of the parser state suitable for use by the caller
23 * of the Parser. The meaning of each state and therefore which action
24 * the caller should perform on that state is not self-evident. In particular,
25 * it depends on which parser is used (currently {@link HtmlParser} and
26 * {@link JavascriptParser}). For examples, you will have to look
27 * at the <code>Google Template System</code> and <code>ClearSilver</code>
28 * both of which support Auto-Escaping by interfacing with our parser
29 * (using the parser written in C++).
30 *
31 * <p>The caller of the Parser will query for the current parser state at
32 * points of interest during parsing of templates. Based on the parser's
33 * current state as represented by this class, the caller can determine
34 * the appropriate escaping to apply.
35 *
36 * <p>Note: Given this class is external-facing, I considered creating
37 * an interface but it is not likely we'll ever need to add more flexibility
38 * and the class is so simple, I figured it was not warranted.
39 *
40 *
41 * @see HtmlParser
42 * @see JavascriptParser
43 */
44public class ExternalState {
45
46  private final String name;
47
48  /**
49   * Creates an {@code ExternalState} object.
50   *
51   * @param name the name to assign to that state
52   * @see HtmlParser
53   * @see JavascriptParser
54   */
55  public ExternalState(String name) {
56    Preconditions.checkNotNull(name);   // Developer error if it happens.
57    this.name = name;
58  }
59
60  /**
61   * Returns the name of the object. The name is only needed
62   * to provide human-readable information when debugging.
63   *
64   * @return the name of that object
65   */
66  public String getName() {
67    return name;
68  }
69
70  /**
71   * Returns the string representation of this external state.
72   * The details of this representation are subject to change.
73   */
74  @Override
75  public String toString() {
76    return String.format("ExternalState: %s", name);
77  }
78}
79