1 package org.exolab.castor.xml.parsing;
2
3 import org.exolab.castor.xml.UnmarshalHandler;
4
5 /**
6 * A helper class for {@link UnmarshalHandler}.
7 *
8 * Keeps track if elements, which appear in XML but for which there is no mapping, should be
9 * allowed.
10 *
11 * @author <a href="mailto:philipp DOT erlacher AT gmail DOT com">Philipp Erlacher</a>
12 *
13 * @since 1.3.2
14 */
15 public class StrictElementHandler {
16
17 /**
18 * A boolean that indicates element processing should be strict and an error should be flagged if
19 * any extra elements exist.
20 **/
21 private boolean _strictElements = true;
22
23 /**
24 * A depth counter that increases as we skip elements ( in startElement ) and decreases as we
25 * process and endElement. Only active if _strictElements is set.
26 */
27 private int _ignoreElementDepth = 0;
28
29 /**
30 * Sets whether or not elements that do not match a specific field should simply be ignored or
31 * reported as an error. By default, extra elements are ignored.
32 *
33 * @param ignoreExtraElems a boolean that when true will allow non-matched attributes to simply be
34 * ignored.
35 **/
36 public void setIgnoreExtraElements(boolean ignoreExtraElems) {
37 _strictElements = (!ignoreExtraElems);
38 }
39
40 /**
41 * Checks if extra elements will be ignored.
42 *
43 * @return true if we ignore extra elements, false otherwise
44 */
45 public boolean areElementsIgnorable() {
46 return !_strictElements;
47 }
48
49 /**
50 * Skip element that appear in XML but for which we have no mapping
51 *
52 * @return
53 */
54 public boolean skipElement() {
55 return _ignoreElementDepth > 0;
56 }
57
58 /**
59 * Checks if a start element can be skipped
60 *
61 * @return true if start element can be skipped, false otherwise
62 */
63 public boolean skipStartElement() {
64 if (areElementsIgnorable() && skipElement()) {
65 addIgnorableElement();
66 return true;
67 }
68 return false;
69 }
70
71 /**
72 * Checks if a start element can be skipped omitting current value of element depth.
73 *
74 * @return true if start element can be skipped, false otherwise
75 */
76 public boolean skipStartElementIgnoringDepth() {
77 if (areElementsIgnorable()) {
78 addIgnorableElement();
79 return true;
80 }
81 return false;
82 }
83
84 /**
85 * Checks if an end element can be skipped.
86 *
87 * @return true if end element can be skipped, false otherwise
88 */
89 public boolean skipEndElement() {
90 if (skipElement()) {
91 remIgnorableElement();
92 return true;
93 }
94 return false;
95 }
96
97 /**
98 * Decreases the depth counter for elements which should be skipped.
99 */
100 private void remIgnorableElement() {
101 --_ignoreElementDepth;
102 }
103
104 /**
105 * Increases the depth counter for elements for which we have no mapping.
106 */
107 private void addIgnorableElement() {
108 ++_ignoreElementDepth;
109 }
110 }