xaddbase.java

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

package org.xmlsh.internal.commands;

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 javax.xml.namespace.QName;
import javax.xml.stream.XMLEventFactory;
import javax.xml.stream.XMLEventReader;
import javax.xml.stream.XMLEventWriter;
import javax.xml.stream.XMLStreamConstants;
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;
import javanet.staxutils.XMLStreamUtils;

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() == XMLStreamConstants.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() == XMLStreamConstants.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.
//