xaddbase.java

/**
 * $Id: $
 * $Date: $
 *
 */

package org.xmlsh.commands.internal;

import java.net.URI;
import java.net.URISyntaxException;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import java.util.Stack;

import javanet.staxutils.XMLStreamUtils;

import javax.xml.namespace.QName;
import javax.xml.stream.XMLEventFactory;
import javax.xml.stream.XMLEventReader;
import javax.xml.stream.XMLEventWriter;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.events.Attribute;
import javax.xml.stream.events.StartElement;
import javax.xml.stream.events.XMLEvent;

import org.xmlsh.core.Options;
import org.xmlsh.core.XCommand;
import org.xmlsh.core.XValue;
import org.xmlsh.sh.shell.SerializeOpts;
import org.xmlsh.util.Util;


public class xaddbase extends XCommand {

	private XMLEventFactory mFactory = XMLEventFactory.newInstance();
	
	private static QName mBaseQName = new QName("http://www.w3.org/XML/1998/namespace","base" , "xml");
	
	@Override
	public int run( List<XValue> args )
	throws Exception 
	{
		boolean		opt_all		= false ;
		boolean		opt_relative = false ;
		
		
		Options opts = new Options( "a=all,r=relative" , SerializeOpts.getOptionDefs()  );
		opts.parse(args);
	
		
		SerializeOpts serializeOpts = getSerializeOpts(opts);
		XMLEventReader reader = getStdin().asXMLEventReader(serializeOpts);
		XMLEventWriter writer = getStdout().asXMLEventWriter(serializeOpts);
		
		opt_all 	= opts.hasOpt("all");
		opt_relative = opts.hasOpt("relative");
		add_base( reader , writer , opt_all , opt_relative , getStdin().getSystemId() );
			
		

	
		return 0;

	}
	
	

	private XMLEvent	add_base_attr( StartElement start , String base)
	{
		Attribute	attr = mFactory.createAttribute(mBaseQName, base);
		return XMLStreamUtils.mergeAttributes(start, Collections.singletonList(attr).iterator(), mFactory);
		
		
		
	}
	
	
	
	


	private String resolve(String parentBaseURI, String baseURI, boolean opt_relative) throws URISyntaxException {
		if(! opt_relative )
			return baseURI ;
		
		if( Util.isBlank(parentBaseURI))
			return baseURI;
		
		
		URI u = new URI( parentBaseURI );
		// Remove final path component from parent 
		String path = u.getPath();
		int slash = path.lastIndexOf('/');
		if( slash >= 0 )
			path = path.substring(0,slash);
		URI parent_URI = 
			new URI(u.getScheme(),
			        u.getUserInfo(), u.getHost(), u.getPort(),
			        path, 
			        u.getQuery(),
			        u.getFragment());

		
		URI base_URI = new URI( baseURI );
		
		URI relative = parent_URI.relativize(base_URI);
		return relative.toString();
	}



	private void add_base(XMLEventReader reader, XMLEventWriter writer, boolean opt_all, boolean opt_relative , String parentURI ) throws URISyntaxException, XMLStreamException 
	{
		Stack<String>	mURIs = new Stack<String>();
		
		mURIs.push(parentURI);
		
		while( reader.hasNext() ){
			XMLEvent event = reader.nextEvent();
			if( event.getEventType() == XMLEvent.START_ELEMENT){
				boolean addBase = false ;
				StartElement start = event.asStartElement();
				
				String baseURI = getBaseURI(start );
				parentURI =  mURIs.lastElement() ;
				
				
				boolean bIsRoot =mURIs.size() == 1; 
				if( bIsRoot ){ // document root
					// First element - always set the xml:base attribute
					addBase = true ;
				}
				else
				if( opt_all )
					addBase = true ;
				else
				if( baseURI.equals(parentURI))
					addBase = false ;
				else
				if( !Util.isEqual(parentURI, baseURI))
					addBase = true;
				
				
				if( addBase ){
					String uri = resolve( parentURI , baseURI , bIsRoot ? false : opt_relative);

					event = add_base_attr(start,uri);
				}
				else
					event = removeBase( start );
				
				mURIs.push(baseURI);
			}
			else
			if( event.getEventType() == XMLEvent.END_ELEMENT)
				mURIs.pop();
					
			writer.add(event);
			
		}
		

		
	}


	private String getBaseURI(StartElement start) 
	{
		Attribute baseAttr = start.getAttributeByName( mBaseQName );
		if( baseAttr != null )
			return baseAttr.getValue();
		String systemID = start.getLocation().getSystemId();
		if( Util.isBlank(systemID))
			return "";
		return systemID ;
		
	}

	@SuppressWarnings("unchecked")
	private XMLEvent removeBase(StartElement start) {
		if( start.getAttributeByName(mBaseQName) != null ){
			Iterator iter = start.getAttributes();
			while( iter.hasNext()){
				Attribute a = (Attribute) iter.next();
				if( a.getName().equals(mBaseQName) )
					iter.remove();
			}
		}
		return start ;
			
	}
		


}

//
//
//Copyright (C) 2008-2014    David A. Lee.
//
//The contents of this file are subject to the "Simplified BSD License" (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.opensource.org/licenses/bsd-license.php 
//
//Software distributed under the License is distributed on an "AS IS" basis,
//WITHOUT WARRANTY OF ANY KIND, either express or implied.
//See the License for the specific language governing rights and limitations under the License.
//
//The Original Code is: all this file.
//
//The Initial Developer of the Original Code is David A. Lee
//
//Portions created by (your name) are Copyright (C) (your legal entity). All Rights Reserved.
//
//Contributor(s): none.
//