DocumentHandler.java
// SAX document handler.
// No warranty; no copyright -- use this as you will.
// $Id: DocumentHandler.java,v 1.5 1998/05/01 20:46:02 david Exp $
package org.xml.sax;
/**
* Receive notification of general document events.
*
* <p>This is the main interface that most SAX applications
* implement: if the application needs to be informed of basic parsing
* events, it implements this interface and registers an instance with
* the SAX parser using the setDocumentHandler method. The parser
* uses the instance to report basic document-related events like
* the start and end of elements and character data.</p>
*
* <p>The order of events in this interface is very important, and
* mirrors the order of information in the document itself. For
* example, all of an element's content (character data, processing
* instructions, and/or subelements) will appear, in order, between
* the startElement event and the corresponding endElement event.</p>
*
* <p>Application writers who do not want to implement the entire
* interface can derive a class from HandlerBase, which implements
* the default functionality; parser writers can instantiate
* HandlerBase to obtain a default handler. The application can find
* the location of any document event using the Locator interface
* supplied by the Parser through the setDocumentLocator method.</p>
*
* @author David Megginson (ak117@freenet.carleton.ca)
* @version 1.0
* @see org.xml.sax.Parser#setDocumentHandler
* @see org.xml.sax.Locator
* @see org.xml.sax.HandlerBase
*/
public interface DocumentHandler {
/**
* Receive an object for locating the origin of SAX document events.
*
* <p>SAX parsers are strongly encouraged (though not absolutely
* required) to supply a locator: if it does so, it must supply
* the locator to the application by invoking this method before
* invoking any of the other methods in the DocumentHandler
* interface.</p>
*
* <p>The locator allows the application to determine the end
* position of any document-related event, even if the parser is
* not reporting an error. Typically, the application will
* use this information for reporting its own errors (such as
* character content that does not match an application's
* business rules). The information returned by the locator
* is probably not sufficient for use with a search engine.</p>
*
* <p>Note that the locator will return correct information only
* during the invocation of the events in this interface. The
* application should not attempt to use it at any other time.</p>
*
* @param locator An object that can return the location of
* any SAX document event.
* @see org.xml.sax.Locator
*/
public abstract void setDocumentLocator (Locator locator);
/**
* Receive notification of the beginning of a document.
*
* <p>The SAX parser will invoke this method only once, before any
* other methods in this interface or in DTDHandler (except for
* setDocumentLocator).</p>
*
* @exception org.xml.sax.SAXException Any SAX exception, possibly
* wrapping another exception.
*/
public abstract void startDocument ()
throws SAXException;
/**
* Receive notification of the end of a document.
*
* <p>The SAX parser will invoke this method only once, and it will
* be the last method invoked during the parse. The parser shall
* not invoke this method until it has either abandoned parsing
* (because of an unrecoverable error) or reached the end of
* input.</p>
*
* @exception org.xml.sax.SAXException Any SAX exception, possibly
* wrapping another exception.
*/
public abstract void endDocument ()
throws SAXException;
/**
* Receive notification of the beginning of an element.
*
* <p>The Parser will invoke this method at the beginning of every
* element in the XML document; there will be a corresponding
* endElement() event for every startElement() event (even when the
* element is empty). All of the element's content will be
* reported, in order, before the corresponding endElement()
* event.</p>
*
* <p>If the element name has a namespace prefix, the prefix will
* still be attached. Note that the attribute list provided will
* contain only attributes with explicit values (specified or
* defaulted): #IMPLIED attributes will be omitted.</p>
*
* @param name The element type name.
* @param atts The attributes attached to the element, if any.
* @exception org.xml.sax.SAXException Any SAX exception, possibly
* wrapping another exception.
* @see #endElement
* @see org.xml.sax.AttributeList
*/
public abstract void startElement (String name, AttributeList atts)
throws SAXException;
/**
* Receive notification of the end of an element.
*
* <p>The SAX parser will invoke this method at the end of every
* element in the XML document; there will be a corresponding
* startElement() event for every endElement() event (even when the
* element is empty).</p>
*
* <p>If the element name has a namespace prefix, the prefix will
* still be attached to the name.</p>
*
* @param name The element type name
* @exception org.xml.sax.SAXException Any SAX exception, possibly
* wrapping another exception.
*/
public abstract void endElement (String name)
throws SAXException;
/**
* Receive notification of character data.
*
* <p>The Parser will call this method to report each chunk of
* character data. SAX parsers may return all contiguous character
* data in a single chunk, or they may split it into several
* chunks; however, all of the characters in any single event
* must come from the same external entity, so that the Locator
* provides useful information.</p>
*
* <p>The application must not attempt to read from the array
* outside of the specified range.</p>
*
* <p>Note that some parsers will report whitespace using the
* ignorableWhitespace() method rather than this one (validating
* parsers must do so).</p>
*
* @param ch The characters from the XML document.
* @param start The start position in the array.
* @param length The number of characters to read from the array.
* @exception org.xml.sax.SAXException Any SAX exception, possibly
* wrapping another exception.
* @see #ignorableWhitespace
* @see org.xml.sax.Locator
*/
public abstract void characters (char ch[], int start, int length)
throws SAXException;
/**
* Receive notification of ignorable whitespace in element content.
*
* <p>Validating Parsers must use this method to report each chunk
* of ignorable whitespace (see the W3C XML 1.0 recommendation,
* section 2.10): non-validating parsers may also use this method
* if they are capable of parsing and using content models.</p>
*
* <p>SAX parsers may return all contiguous whitespace in a single
* chunk, or they may split it into several chunks; however, all of
* the characters in any single event must come from the same
* external entity, so that the Locator provides useful
* information.</p>
*
* <p>The application must not attempt to read from the array
* outside of the specified range.</p>
*
* @param ch The characters from the XML document.
* @param start The start position in the array.
* @param length The number of characters to read from the array.
* @exception org.xml.sax.SAXException Any SAX exception, possibly
* wrapping another exception.
* @see #characters
*/
public abstract void ignorableWhitespace (char ch[], int start, int length)
throws SAXException;
/**
* Receive notification of a processing instruction.
*
* <p>The Parser will invoke this method once for each processing
* instruction found: note that processing instructions may occur
* before or after the main document element.</p>
*
* <p>A SAX parser should never report an XML declaration (XML 1.0,
* section 2.8) or a text declaration (XML 1.0, section 4.3.1)
* using this method.</p>
*
* @param target The processing instruction target.
* @param data The processing instruction data, or null if
* none was supplied.
* @exception org.xml.sax.SAXException Any SAX exception, possibly
* wrapping another exception.
*/
public abstract void processingInstruction (String target, String data)
throws SAXException;
}