ContentHandler.java
// ContentHandler.java - handle main document content.
// Written by David Megginson, sax@megginson.com
// NO WARRANTY! This class is in the public domain.
// $Id: ContentHandler.java,v 1.2 2000/01/21 15:15:38 david Exp $
package org.xml.sax;
/**
* Receive notification of the logical content of a document.
*
* <blockquote>
* <em>This module, both source code and documentation, is in the
* Public Domain, and comes with <strong>NO WARRANTY</strong>.</em>
* </blockquote>
*
* <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>This interface is based on the now-deprecated SAX 1.0
* DocumentHandler interface, but it adds support for Namespaces
* and for reporting skipped entitys (in non-validating XML
* processors).</p>
*
* @since SAX 2.0
* @author David Megginson,
* <a href="mailto:sax@megginson.com">sax@megginson.com</a>
* @version 2.0beta
* @see org.xml.sax.XMLReader
* @see org.xml.sax.DTDHandler
* @see org.xml.sax.ErrorHandler
*/
public interface ContentHandler
{
/**
* 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 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 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 void endDocument()
throws SAXException;
/**
* Begin the scope of a prefix-URI Namespace mapping.
*
* <p>The information from this event is not necessary for
* normal Namespace processing: the SAX XML reader will
* automatically replace prefixes for element and attribute
* names when the http://xml.org/sax/features/namespaces
* feature is true (the default).</p>
*
* <p>There are cases, however, when applications need to
* use prefixes in character data or in attribute values,
* where they cannot safely be expanded automatically; the
* start/endPrefixMapping event supplies the information
* to the application to expand prefixes in those contexts
* itself, if necessary.</p>
*
* <p>Note that start/endPrefixMapping events are not
* guaranteed to be properly nested relative to each-other:
* all startPrefixMapping events will occur before the
* corresponding startElement event, and all endPrefixMapping
* events will occur after the corresponding endElement event,
* but their order is not guaranteed.</p>
*
* @param prefix The Namespace prefix being declared.
* @param uri The Namespace URI the prefix is mapped to.
* @exception org.xml.sax.SAXException The client may throw
* an exception during processing.
* @see #endPrefixMapping
* @see #startElement
*/
public void startPrefixMapping (String prefix, String uri)
throws SAXException;
/**
* End the scope of a prefix-URI mapping.
*
* <p>See startPrefixMapping for details. This event will
* always occur after the corresponding endElement event,
* but the order of endPrefixMapping events is not otherwise
* guaranteed.</p>
*
* @param prefix The prefix that was being mapping.
* @exception org.xml.sax.SAXException The client may throw
* an exception during processing.
* @see #startPrefixMapping
* @see #endElement
*/
public void endPrefixMapping (String prefix)
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>This event allows up to three name components for each
* element:</p>
*
* <ol>
* <li>the Namespace URI;</li>
* <li>the local name; and</li>
* <li>the raw XML 1.0 name.</li>
* </ol>
*
* <p>Any or all of these may be provided, depending on the
* values of the http://xml.org/sax/features/namespaces
* and the http://xml.org/sax/features/raw-names
* properties:</p>
*
* <ul>
* <li>the Namespace URI and local name are required when
* the namespaces property is true (the default), and are
* optional when the namespaces property is false (if one is
* specified, both must be);</li>
* <li>the raw name is required when the raw-names property
* is true, and is optional when the raw-names property
* is false (the default).</li>
* </ul>
*
* <p>Note that the attribute list provided will contain only
* attributes with explicit values (specified or defaulted):
* #IMPLIED attributes will be omitted. The attribute list
* will contain attributes used for Namespace declarations
* (xmlns* attributes) only if the
* http://xml.org/sax/features/raw-names property is true
* (it is false by default, and support for a true value is
* optional).</p>
*
* @param uri The Namespace URI, or the empty string if the
* element has no Namespace URI or if Namespace
* processing is not being performed.
* @param localName The local name (without prefix), or the
* empty string if Namespace processing is not being
* performed.
* @param rawName The raw XML 1.0 name (with prefix), or the
* empty string if raw names are not available.
* @param atts The attributes attached to the element. If
* there are no attributes, it shall be an empty
* Attributes object.
* @exception org.xml.sax.SAXException Any SAX exception, possibly
* wrapping another exception.
* @see #endElement
* @see org.xml.sax.Attributes
*/
public void startElement (String namespaceURI, String localName,
String rawName, Attributes 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>For information on the names, see startElement.</p>
*
* @param uri The Namespace URI, or the empty string if the
* element has no Namespace URI or if Namespace
* processing is not being performed.
* @param localName The local name (without prefix), or the
* empty string if Namespace processing is not being
* performed.
* @param rawName The raw XML 1.0 name (with prefix), or the
* empty string if raw names are not available.
* @exception org.xml.sax.SAXException Any SAX exception, possibly
* wrapping another exception.
*/
public void endElement (String namespaceURI, String localName,
String rawName)
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 <em>must</em> 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 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 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 void processingInstruction (String target, String data)
throws SAXException;
/**
* Receive notification of a skipped entity.
*
* <p>The Parser will invoke this method once for each entity
* skipped. Non-validating processors may skip entities if they
* have not seen the declarations (because, for example, the
* entity was declared in an external DTD subset). All processors
* may skip external entities, depending on the values of the
* http://xml.org/sax/features/external-general-entities and the
* http://xml.org/sax/features/external-parameter-entities
* properties.</p>
*
* @param name The name of the skipped entity. If it is a
* parameter entity, the name will begin with '%'.
* @exception org.xml.sax.SAXException Any SAX exception, possibly
* wrapping another exception.
*/
public void skippedEntity (String name)
throws SAXException;
}
// end of ContentHandler.java