/*
* Copyright 1999-2004 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.cocoon.xml;
import org.apache.avalon.framework.logger.LogEnabled;
import org.apache.avalon.framework.logger.Logger;
import org.xml.sax.Attributes;
import org.xml.sax.DocumentHandler;
import org.xml.sax.Locator;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.AttributeListImpl;
import java.util.Vector;
/**
* This class is an utility class "wrapping" around a SAX version 1.0
* <code>DocumentHandler</code> and forwarding it those events received throug
* its <code>XMLConsumers</code> interface.
* <br>
* This class fully supports XML namespaces, converting
* <code>startPrefixMapping(...)</code> and <code>endPrefixMapping(...)</code>
* calls into appropriate <code>xmlns</code> and <code>xmlns:...</code> element
* attributes.
*
* @author <a href="mailto:pier@apache.org">Pierpaolo Fumagalli</a>
* (Apache Software Foundation)
* @version CVS $Id: DocumentHandlerWrapper.java,v 1.2 2004/03/05 13:03:01 bdelacretaz Exp $
*/
public class DocumentHandlerWrapper extends AbstractXMLConsumer implements LogEnabled /*, Recyclable*/ {
protected Logger log;
/** The current namespaces table. */
private NamespacesTable namespaces=new NamespacesTable();
/** The vector of namespaces declarations to include in the next element. */
private Vector undecl=new Vector();
/** The current <code>DocumentHandler</code>. */
protected DocumentHandler documentHandler=null;
/**
* Create a new <code>DocumentHandlerWrapper</code> instance.
*/
public DocumentHandlerWrapper() {
super();
}
/**
* Create a new <code>DocumentHandlerWrapper</code> instance.
*/
public DocumentHandlerWrapper(DocumentHandler document) {
this();
this.setDocumentHandler(document);
}
/**
* Provide component with a logger.
*
* @param logger the logger
*/
public void enableLogging(Logger logger) {
if (this.log == null) {
this.log = logger;
}
}
/**
* Implementation of the recycle method
*/
public void recycle() {
this.documentHandler = null;
}
/**
* Set the <code>DocumentHandler</code> that will receive XML data.
*
* @exception IllegalStateException If the <code>DocumentHandler</code>
* was already set.
*/
public void setDocumentHandler(DocumentHandler document)
throws IllegalStateException {
if (this.documentHandler!=null) throw new IllegalStateException();
this.documentHandler=document;
}
/**
* Receive an object for locating the origin of SAX document events.
*/
public void setDocumentLocator (Locator locator) {
if (this.documentHandler==null) return;
else this.documentHandler.setDocumentLocator(locator);
}
/**
* Receive notification of the beginning of a document.
*/
public void startDocument ()
throws SAXException {
if (this.documentHandler==null)
throw new SAXException("DocumentHandler not set");
this.documentHandler.startDocument();
}
/**
* Receive notification of the end of a document.
*/
public void endDocument ()
throws SAXException {
if (this.documentHandler==null)
throw new SAXException("DocumentHandler not set");
this.documentHandler.endDocument();
}
/**
* Begin the scope of a prefix-URI Namespace mapping.
*/
public void startPrefixMapping(String prefix, String uri)
throws SAXException {
this.undecl.addElement(this.namespaces.addDeclaration(prefix,uri));
}
/**
* End the scope of a prefix-URI mapping.
*/
public void endPrefixMapping(String prefix)
throws SAXException {
if (namespaces.removeDeclaration(prefix)==null)
throw new SAXException("Namespace prefix \""+prefix+
"\" never declared");
}
/**
* Receive notification of the beginning of an element.
*/
public void startElement(String uri, String loc, String raw, Attributes a)
throws SAXException {
if (this.documentHandler==null)
throw new SAXException("DocumentHandler not set");
NamespacesTable.Name name=this.namespaces.resolve(uri,raw,null,loc);
// Create the AttributeList
AttributeListImpl a2=new AttributeListImpl();
// Set the xmlns:...="..." attributes
if (this.undecl.size()>0) {
for (int x=0; x<this.undecl.size(); x++) {
NamespacesTable.Declaration dec=null;
dec=(NamespacesTable.Declaration)this.undecl.elementAt(x);
String aname="xmlns";
if (dec.getPrefix().length()>0) aname="xmlns:"+dec.getPrefix();
a2.addAttribute(aname,"CDATA",dec.getUri());
}
this.undecl.clear();
}
// Set the real attributes
for (int x=0; x<a.getLength(); x++) {
NamespacesTable.Name aname=namespaces.resolve(a.getURI(x),
a.getQName(x),
null,
a.getLocalName(x));
a2.addAttribute(aname.getQName(),a.getType(x),a.getValue(x));
}
// Call the document handler startElement() method.
this.documentHandler.startElement(name.getQName(),a2);
}
/**
* Receive notification of the end of an element.
*/
public void endElement(String uri, String loc, String raw)
throws SAXException {
if (this.documentHandler==null)
throw new SAXException("DocumentHandler not set");
NamespacesTable.Name name=this.namespaces.resolve(uri,raw,null,loc);
this.documentHandler.endElement(name.getQName());
}
/**
* Receive notification of character data.
*/
public void characters(char ch[], int start, int len)
throws SAXException {
if (this.documentHandler==null)
throw new SAXException("DocumentHandler not set");
this.documentHandler.characters(ch,start,len);
}
/**
* Receive notification of ignorable whitespace in element content.
*/
public void ignorableWhitespace(char ch[], int start, int len)
throws SAXException {
if (this.documentHandler==null)
throw new SAXException("DocumentHandler not set");
this.documentHandler.ignorableWhitespace(ch,start,len);
}
/**
* Receive notification of a processing instruction.
*/
public void processingInstruction(String target, String data)
throws SAXException {
if (this.documentHandler==null)
throw new SAXException("DocumentHandler not set");
this.documentHandler.processingInstruction(target,data);
}
}