001 // SAX document handler.
002 // http://www.saxproject.org
003 // No warranty; no copyright -- use this as you will.
004 // $Id: DocumentHandler.java,v 1.1 2004/12/23 22:38:42 mark Exp $
005
006 package org.xml.sax;
007
008 /**
009 * Receive notification of general document events.
010 *
011 * <blockquote>
012 * <em>This module, both source code and documentation, is in the
013 * Public Domain, and comes with <strong>NO WARRANTY</strong>.</em>
014 * See <a href='http://www.saxproject.org'>http://www.saxproject.org</a>
015 * for further information.
016 * </blockquote>
017 *
018 * <p>This was the main event-handling interface for SAX1; in
019 * SAX2, it has been replaced by {@link org.xml.sax.ContentHandler
020 * ContentHandler}, which provides Namespace support and reporting
021 * of skipped entities. This interface is included in SAX2 only
022 * to support legacy SAX1 applications.</p>
023 *
024 * <p>The order of events in this interface is very important, and
025 * mirrors the order of information in the document itself. For
026 * example, all of an element's content (character data, processing
027 * instructions, and/or subelements) will appear, in order, between
028 * the startElement event and the corresponding endElement event.</p>
029 *
030 * <p>Application writers who do not want to implement the entire
031 * interface can derive a class from HandlerBase, which implements
032 * the default functionality; parser writers can instantiate
033 * HandlerBase to obtain a default handler. The application can find
034 * the location of any document event using the Locator interface
035 * supplied by the Parser through the setDocumentLocator method.</p>
036 *
037 * @deprecated This interface has been replaced by the SAX2
038 * {@link org.xml.sax.ContentHandler ContentHandler}
039 * interface, which includes Namespace support.
040 * @since SAX 1.0
041 * @author David Megginson
042 * @version 2.0.1 (sax2r2)
043 * @see org.xml.sax.Parser#setDocumentHandler
044 * @see org.xml.sax.Locator
045 * @see org.xml.sax.HandlerBase
046 */
047 public interface DocumentHandler {
048
049
050 /**
051 * Receive an object for locating the origin of SAX document events.
052 *
053 * <p>SAX parsers are strongly encouraged (though not absolutely
054 * required) to supply a locator: if it does so, it must supply
055 * the locator to the application by invoking this method before
056 * invoking any of the other methods in the DocumentHandler
057 * interface.</p>
058 *
059 * <p>The locator allows the application to determine the end
060 * position of any document-related event, even if the parser is
061 * not reporting an error. Typically, the application will
062 * use this information for reporting its own errors (such as
063 * character content that does not match an application's
064 * business rules). The information returned by the locator
065 * is probably not sufficient for use with a search engine.</p>
066 *
067 * <p>Note that the locator will return correct information only
068 * during the invocation of the events in this interface. The
069 * application should not attempt to use it at any other time.</p>
070 *
071 * @param locator An object that can return the location of
072 * any SAX document event.
073 * @see org.xml.sax.Locator
074 */
075 public abstract void setDocumentLocator (Locator locator);
076
077
078 /**
079 * Receive notification of the beginning of a document.
080 *
081 * <p>The SAX parser will invoke this method only once, before any
082 * other methods in this interface or in DTDHandler (except for
083 * setDocumentLocator).</p>
084 *
085 * @exception org.xml.sax.SAXException Any SAX exception, possibly
086 * wrapping another exception.
087 */
088 public abstract void startDocument ()
089 throws SAXException;
090
091
092 /**
093 * Receive notification of the end of a document.
094 *
095 * <p>The SAX parser will invoke this method only once, and it will
096 * be the last method invoked during the parse. The parser shall
097 * not invoke this method until it has either abandoned parsing
098 * (because of an unrecoverable error) or reached the end of
099 * input.</p>
100 *
101 * @exception org.xml.sax.SAXException Any SAX exception, possibly
102 * wrapping another exception.
103 */
104 public abstract void endDocument ()
105 throws SAXException;
106
107
108 /**
109 * Receive notification of the beginning of an element.
110 *
111 * <p>The Parser will invoke this method at the beginning of every
112 * element in the XML document; there will be a corresponding
113 * endElement() event for every startElement() event (even when the
114 * element is empty). All of the element's content will be
115 * reported, in order, before the corresponding endElement()
116 * event.</p>
117 *
118 * <p>If the element name has a namespace prefix, the prefix will
119 * still be attached. Note that the attribute list provided will
120 * contain only attributes with explicit values (specified or
121 * defaulted): #IMPLIED attributes will be omitted.</p>
122 *
123 * @param name The element type name.
124 * @param atts The attributes attached to the element, if any.
125 * @exception org.xml.sax.SAXException Any SAX exception, possibly
126 * wrapping another exception.
127 * @see #endElement
128 * @see org.xml.sax.AttributeList
129 */
130 public abstract void startElement (String name, AttributeList atts)
131 throws SAXException;
132
133
134 /**
135 * Receive notification of the end of an element.
136 *
137 * <p>The SAX parser will invoke this method at the end of every
138 * element in the XML document; there will be a corresponding
139 * startElement() event for every endElement() event (even when the
140 * element is empty).</p>
141 *
142 * <p>If the element name has a namespace prefix, the prefix will
143 * still be attached to the name.</p>
144 *
145 * @param name The element type name
146 * @exception org.xml.sax.SAXException Any SAX exception, possibly
147 * wrapping another exception.
148 */
149 public abstract void endElement (String name)
150 throws SAXException;
151
152
153 /**
154 * Receive notification of character data.
155 *
156 * <p>The Parser will call this method to report each chunk of
157 * character data. SAX parsers may return all contiguous character
158 * data in a single chunk, or they may split it into several
159 * chunks; however, all of the characters in any single event
160 * must come from the same external entity, so that the Locator
161 * provides useful information.</p>
162 *
163 * <p>The application must not attempt to read from the array
164 * outside of the specified range.</p>
165 *
166 * <p>Note that some parsers will report whitespace using the
167 * ignorableWhitespace() method rather than this one (validating
168 * parsers must do so).</p>
169 *
170 * @param ch The characters from the XML document.
171 * @param start The start position in the array.
172 * @param length The number of characters to read from the array.
173 * @exception org.xml.sax.SAXException Any SAX exception, possibly
174 * wrapping another exception.
175 * @see #ignorableWhitespace
176 * @see org.xml.sax.Locator
177 */
178 public abstract void characters (char ch[], int start, int length)
179 throws SAXException;
180
181
182 /**
183 * Receive notification of ignorable whitespace in element content.
184 *
185 * <p>Validating Parsers must use this method to report each chunk
186 * of ignorable whitespace (see the W3C XML 1.0 recommendation,
187 * section 2.10): non-validating parsers may also use this method
188 * if they are capable of parsing and using content models.</p>
189 *
190 * <p>SAX parsers may return all contiguous whitespace in a single
191 * chunk, or they may split it into several chunks; however, all of
192 * the characters in any single event must come from the same
193 * external entity, so that the Locator provides useful
194 * information.</p>
195 *
196 * <p>The application must not attempt to read from the array
197 * outside of the specified range.</p>
198 *
199 * @param ch The characters from the XML document.
200 * @param start The start position in the array.
201 * @param length The number of characters to read from the array.
202 * @exception org.xml.sax.SAXException Any SAX exception, possibly
203 * wrapping another exception.
204 * @see #characters
205 */
206 public abstract void ignorableWhitespace (char ch[], int start, int length)
207 throws SAXException;
208
209
210 /**
211 * Receive notification of a processing instruction.
212 *
213 * <p>The Parser will invoke this method once for each processing
214 * instruction found: note that processing instructions may occur
215 * before or after the main document element.</p>
216 *
217 * <p>A SAX parser should never report an XML declaration (XML 1.0,
218 * section 2.8) or a text declaration (XML 1.0, section 4.3.1)
219 * using this method.</p>
220 *
221 * @param target The processing instruction target.
222 * @param data The processing instruction data, or null if
223 * none was supplied.
224 * @exception org.xml.sax.SAXException Any SAX exception, possibly
225 * wrapping another exception.
226 */
227 public abstract void processingInstruction (String target, String data)
228 throws SAXException;
229
230 }
231
232 // end of DocumentHandler.java