/*
* Copyright 1999,2000,2004 The Apache Software Foundation.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.html.dom;
import java.util.Vector;
import org.apache.xerces.dom.ElementImpl;
import org.apache.xerces.dom.ProcessingInstructionImpl;
import org.apache.xerces.dom.TextImpl;
import org.w3c.dom.Node;
import org.w3c.dom.html.HTMLDocument;
import org.xml.sax.AttributeList;
import org.xml.sax.DocumentHandler;
import org.xml.sax.Locator;
import org.xml.sax.SAXException;
/**
* This is a SAX document handler that is used to build an HTML document.
* It can build a document from any SAX parser, but is specifically tuned
* for working with the OpenXML HTML parser.
*
*
* @version $Revision: 319808 $ $Date: 2004-02-24 18:34:05 -0500 (Tue, 24 Feb 2004) $
* @author <a href="mailto:arkin@openxml.org">Assaf Arkin</a>
*/
public class HTMLBuilder
implements DocumentHandler
{
/**
* The document that is being built.
*/
protected HTMLDocumentImpl _document;
/**
* The current node in the document into which elements, text and
* other nodes will be inserted. This starts as the document iself
* and reflects each element that is currently being parsed.
*/
protected ElementImpl _current;
/**
* A reference to the current locator, this is generally the parser
* itself. The locator is used to locate errors and identify the
* source locations of elements.
*/
private Locator _locator;
/**
* Applies only to whitespace appearing between element tags in element content,
* as per the SAX definition, and true by default.
*/
private boolean _ignoreWhitespace = true;
/**
* Indicates whether finished building a document. If so, can start building
* another document. Must be initially true to get the first document processed.
*/
private boolean _done = true;
/**
* The document is only created the same time as the document element, however, certain
* nodes may precede the document element (comment and PI), and they are accumulated
* in this vector.
*/
protected Vector _preRootNodes;
public void startDocument()
throws SAXException
{
if ( ! _done )
throw new SAXException( "HTM001 State error: startDocument fired twice on one builder." );
_document = null;
_done = false;
}
public void endDocument()
throws SAXException
{
if ( _document == null )
throw new SAXException( "HTM002 State error: document never started or missing document element." );
if ( _current != null )
throw new SAXException( "HTM003 State error: document ended before end of document element." );
_current = null;
_done = true;
}
public synchronized void startElement( String tagName, AttributeList attrList )
throws SAXException
{
ElementImpl elem;
int i;
if ( tagName == null )
throw new SAXException( "HTM004 Argument 'tagName' is null." );
// If this is the root element, this is the time to create a new document,
// because only know we know the document element name and namespace URI.
if ( _document == null )
{
// No need to create the element explicitly.
_document = new HTMLDocumentImpl();
elem = (ElementImpl) _document.getDocumentElement();
_current = elem;
if ( _current == null )
throw new SAXException( "HTM005 State error: Document.getDocumentElement returns null." );
// Insert nodes (comment and PI) that appear before the root element.
if ( _preRootNodes != null )
{
for ( i = _preRootNodes.size() ; i-- > 0 ; )
_document.insertBefore( (Node) _preRootNodes.elementAt( i ), elem );
_preRootNodes = null;
}
}
else
{
// This is a state error, indicates that document has been parsed in full,
// or that there are two root elements.
if ( _current == null )
throw new SAXException( "HTM006 State error: startElement called after end of document element." );
elem = (ElementImpl) _document.createElement( tagName );
_current.appendChild( elem );
_current = elem;
}
// Add the attributes (specified and not-specified) to this element.
if ( attrList != null )
{
for ( i = 0 ; i < attrList.getLength() ; ++ i )
elem.setAttribute( attrList.getName( i ), attrList.getValue( i ) );
}
}
public void endElement( String tagName )
throws SAXException
{
if ( _current == null )
throw new SAXException( "HTM007 State error: endElement called with no current node." );
if ( ! _current.getNodeName().equalsIgnoreCase( tagName ))
throw new SAXException( "HTM008 State error: mismatch in closing tag name " + tagName + "\n" + tagName);
// Move up to the parent element. When you reach the top (closing the root element).
// the parent is document and current is null.
if ( _current.getParentNode() == _current.getOwnerDocument() )
_current = null;
else
_current = (ElementImpl) _current.getParentNode();
}
public void characters( String text )
throws SAXException
{
if ( _current == null )
throw new SAXException( "HTM009 State error: character data found outside of root element." );
_current.appendChild( new TextImpl( _document, text ) );
}
public void characters( char[] text, int start, int length )
throws SAXException
{
if ( _current == null )
throw new SAXException( "HTM010 State error: character data found outside of root element." );
_current.appendChild( new TextImpl( _document, new String( text, start, length ) ) );
}
public void ignorableWhitespace( char[] text, int start, int length )
throws SAXException
{
Node node;
if ( ! _ignoreWhitespace )
_current.appendChild( new TextImpl( _document, new String( text, start, length ) ) );
}
public void processingInstruction( String target, String instruction )
throws SAXException
{
Node node;
// Processing instruction may appear before the document element (in fact, before the
// document has been created, or after the document element has been closed.
if ( _current == null && _document == null )
{
if ( _preRootNodes == null )
_preRootNodes = new Vector();
_preRootNodes.addElement( new ProcessingInstructionImpl( null, target, instruction ) );
}
else
if ( _current == null && _document != null )
_document.appendChild( new ProcessingInstructionImpl( _document, target, instruction ) );
else
_current.appendChild( new ProcessingInstructionImpl( _document, target, instruction ) );
}
public HTMLDocument getHTMLDocument()
{
return (HTMLDocument) _document;
}
public void setDocumentLocator( Locator locator )
{
_locator = locator;
}
}