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019     * SAX2, it has been replaced by {@link org.xml.sax.ContentHandler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037     * @deprecated This interface has been replaced by the SAX2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