/*
 * Transformer.java
 * Copyright (C) 2004 The Free Software Foundation
 * 
 * This file is part of GNU JAXP, a library.
 *
 * GNU JAXP 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.
 * 
 * GNU JAXP 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 program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * Linking this library statically or dynamically with other modules is
 * making a combined work based on this library.  Thus, the terms and
 * conditions of the GNU General Public License cover the whole
 * combination.
 *
 * As a special exception, the copyright holders of this library give you
 * permission to link this library with independent modules to produce an
 * executable, regardless of the license terms of these independent
 * modules, and to copy and distribute the resulting executable under
 * terms of your choice, provided that you also meet, for each linked
 * independent module, the terms and conditions of the license of that
 * module.  An independent module is a module which is not derived from
 * or based on this library.  If you modify this library, you may extend
 * this exception to your version of the library, but you are not
 * obliged to do so.  If you do not wish to do so, delete this
 * exception statement from your version. 
 */

package javax.xml.transform;

import java.util.Properties;

/**
 * An XSL transformation.
 * Instances of this class may be reused, but the same instance may not be
 * used concurrently by different threads.
 *
 * @author <a href='mailto:dog@gnu.org'>Chris Burdess</a>
 */
public abstract class Transformer
{

  protected Transformer()
  {
  }

  /**
   * Transforms the source XML to a result tree.
   * @param xmlSource the XML source
   * @param outputTarget the result of the transformation
   */
  public abstract void transform(Source xmlSource, Result outputTarget) 
    throws TransformerException;
  
  /**
   * Sets a parameter value for the transformation.
   * Parameters may be referenced in the XSLT stylesheet.
   * @param name the parameter name (an XML Name, or a namespace-prefixed
   * XML Name of the form <code>{<i>namespaceURI</i>}<i>localName</i></code>
   * @param value the value to assign
   */
  public abstract void setParameter(String name, Object value);

  /**
   * Returns the specified parameter value.
   * @param name the parameter name (an XML Name, or a namespace-prefixed
   * XML Name of the form <code>{<i>namespaceURI</i>}<i>localName</i></code>
   */
  public abstract Object getParameter(String name);

  /**
   * Clears all parameter values.
   */
  public abstract void clearParameters();

  /**
   * Sets the callback used to resolve entities referenced by
   * <code>xsl:include</code>, <code>xsl:import</code>, or the XPath
   * <code>document()</code> function.
   */
  public abstract void setURIResolver(URIResolver resolver);

  /**
   * Returns the callback used to resolve entities referenced by
   * <code>xsl:include</code>, <code>xsl:import</code>, or the XPath
   * <code>document()</code> function.
   */
  public abstract URIResolver getURIResolver();

  /**
   * Sets the output properties for the transformation, overriding any
   * properties defined in the stylesheet.
   * The format of property keys is as in the
   * {@link #setOutputProperty(java.lang.String,java.lang.String)} method.
   * @param oformat a set of output properties, or null to reset all the
   * properties to their default values
   */
  public abstract void setOutputProperties(Properties oformat) 
    throws IllegalArgumentException;

  /**
   * Returns a copy of the output properties for the transformation.
   * Missing properties are defaulted according the
   * <a href='http://www.w3.org/TR/xslt#output'>XSLT Recommendation, section
   * 16</a>: <code>getProperty(String)</code> returns all properties
   * including defaulted ones, and <code>get(Object)</code> returns only the
   * properties explicitly set in the stylesheet.
   */
  public abstract Properties getOutputProperties();

  /**
   * Sets an output property for the transformation, overriding any property
   * of the same name defined in the stylesheet.
   * @param name the property name (an XML Name, or a namespace-prefixed
   * XML Name of the form <code>{<i>namespaceURI</i>}<i>localName</i></code>
   * @param value the string value of the property
   * @exception IllegalArgumentException if the property is not supported
   */
  public abstract void setOutputProperty(String name, String value) 
    throws IllegalArgumentException;

  /**
   * Returns the value of an output property for the transformation.
   * Only explicit properties set programmatically or defined in the
   * stylesheet, not defaulted properties, are returned by this method.
   * @param name the property name (an XML Name, or a namespace-prefixed
   * XML Name of the form <code>{<i>namespaceURI</i>}<i>localName</i></code>
   * @exception IllegalArgumentException if the property is not supported
   */
  public abstract String getOutputProperty(String name) 
    throws IllegalArgumentException;

  /**
   * Sets the callback used to report errors during the transformation.
   *  @exception IllegalArgumentException if the listener is null
   */
  public abstract void setErrorListener(ErrorListener listener)
    throws IllegalArgumentException;
  
  /**
   * Returns the callback used to report errors during the transformation.
   */
  public abstract ErrorListener getErrorListener();

  // -- JAXP 1.3 methods --

  /**
   * Reset this Transformer to its original configuration.
   * @since 1.3
   */
  public void reset()
  {
  }

}
