/* ----------------------------------------------------------------------------
   The Kiwi Toolkit - A Java Class Library
   Copyright (C) 1998-2004 Mark A. Lindner

   This library is free software; you can redistribute it and/or
   modify it under the terms of the GNU General Public License as
   published by the Free Software Foundation; either version 2 of the
   License, or (at your option) any later version.

   This library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this library; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
   02111-1307, USA.
 
   The author may be contacted at: mark_a_lindner@yahoo.com
   ----------------------------------------------------------------------------
   $Log: XMLElement.java,v $
   Revision 1.2  2004/05/05 22:47:37  markl
   comment block updates

   Revision 1.1  2004/05/05 18:47:08  markl
   classes renamed

   Revision 1.6  2003/11/07 19:05:41  markl
   javadoc corrections

   Revision 1.5  2003/01/19 09:34:27  markl
   Javadoc & comment header updates.

   Revision 1.4  2001/03/12 06:10:57  markl
   Javadoc cleanup.

   Revision 1.3  2001/03/12 02:18:29  markl
   Source code cleanup.

   Revision 1.2  1999/01/10 03:37:18  markl
   added GPL header & RCS tag
   ----------------------------------------------------------------------------
*/

package kiwi.text;

import java.util.*;

/** This class represents an XML element. It includes the element tag as well
  * as a hash table of all of the tag's parameters and their values.
  * <p>
  * An example XML element might look like this:
  * <p>
  * <code>
  * &lt;img src=&quot;image.gif&quot; width=100 height=150&gt;
  * </code>
  * <p>
  * In this case <tt>img</tt> is the tag, and <tt>src</tt>, <tt>width</tt> and
  * <tt>height</tt> are the parameters, with values <tt>image.gif</tt>,
  * <tt>100</tt> and <tt>150</tt>, respectively.
  *
  * @author Mark Lindner
  */

public class XMLElement extends Object
  {
  private String tag;
  private Hashtable params;
  private boolean end;

  /** Construct a new <code>XMLElement</code>.
    *
    * @param tag The element's tag.
    * @param end A boolean flag specifying whether this is an end tag. For
    * example, <code></b></code> is an end tag.
    */

  public XMLElement(String tag, boolean end)
    {
    this.tag = tag;
    this.end = end;
    params = new Hashtable();
    }

  /** Construct a new <code>XMLElement</code>. The tag is set to the empty
    * string and the end flag is set to <code>false</code>.
    */

  public XMLElement()
    {
    this("", false);
    }

  /** Check if this is an end tag.
    *
    * @return <code>true</code> if this is an end tag and <code>false</code>
    * otherwise.
    */

  public boolean isEnd()
    {
    return(end);
    }

  /** Set the end tag flag.
    *
    * @param end The new end tag flag value.
    */

  public void setEnd(boolean end)
    {
    this.end = end;
    }

  /** Set the tag.
    *
    * @param tag The new tag.
    */

  public void setTag(String tag)
    {
    this.tag = tag.toLowerCase();
    }

  /** Get the tag.
    *
    * @return The element's tag.
    */

  public String getTag()
    {
    return(tag);
    }

  /** Add a parameter. Adds a parameter to the element's parameter list.
    * If there is already a parameter with the given name in the list, it is
    * replaced.
    *
    * @param name The name of the parameter.
    * @param value The value of the parameter (may be <code>null</code>).
    */

  public void addParam(String name, String value)
    {
    if(value == null)
      params.put(name.toLowerCase(), Void.class);
    else
      params.put(name.toLowerCase(), value);
    }

  /** Get a parameter value. Returns the value for the named paramter.
    *
    * @param name The name of the parameter.
    *
    * @return The value of the named parameter, or <code>null</code> if it's a
    * valueless parameter.
    */

  public String getParamValue(String name)
    {
    Object o = params.get(name);
    if(o != null)
      if(o instanceof String)
        return((String)o);

    return(null);
    }

  /** Get parameter names. Returns an enumeration of strings representing
    * the list of all parameters defined for this element.
    */

  public Enumeration getParamNames()
    {
    return(params.keys());
    }

  /** Create a string representatin of the element. */

  public String toString()
    {
    StringBuffer s = new StringBuffer(50);

    s.append('<');
    if(end) s.append('/');
    s.append(tag);

    for(Enumeration e = getParamNames(); e.hasMoreElements();)
      {
      String key = (String)e.nextElement();

      s.append(' ');
      s.append(key);
      String val = getParamValue(key);
      if(val != null)
        {
        s.append('=');
        s.append('"');
        s.append((String)val);
        s.append('"');
        }
      }
    s.append('>');
    return(s.toString());
    }

  }

/* end of source file */