code: /*
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements. See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership. The ASF licenses this file
   * to you 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.
   */
  /*
   * $Id$
   */
  package org.apache.xalan.processor;
  
  import org.apache.xalan.res.XSLTErrorResources;
  import org.apache.xalan.templates.NamespaceAlias;
  import org.xml.sax.Attributes;
  
  /**
   * TransformerFactory for xsl:namespace-alias markup.
   * A stylesheet can use the xsl:namespace-alias element to
   * declare that one namespace URI is an alias for another namespace URI.
   * <pre>
   * <!ELEMENT xsl:namespace-alias EMPTY>
   * <!ATTLIST xsl:namespace-alias
   *   stylesheet-prefix CDATA #REQUIRED
   *   result-prefix CDATA #REQUIRED
   * >
   * </pre>
   * @see <a href="http://www.w3.org/TR/xslt#dtd">XSLT DTD</a>
   * @see <a href="http://www.w3.org/TR/xslt#literal-result-element">literal-result-element in XSLT Specification</a>
   */
  class ProcessorNamespaceAlias extends XSLTElementProcessor
  {
      static final long serialVersionUID = -6309867839007018964L;
  
    /**
     * Receive notification of the start of an xsl:namespace-alias element.
     *
     * @param handler The calling StylesheetHandler/TemplatesBuilder.
     * @param uri The Namespace URI, or the empty string if the
     *        element has no Namespace URI or if Namespace
     *        processing is not being performed.
     * @param localName The local name (without prefix), or the
     *        empty string if Namespace processing is not being
     *        performed.
     * @param rawName The raw XML 1.0 name (with prefix), or the
     *        empty string if raw names are not available.
     * @param attributes The attributes attached to the element.  If
     *        there are no attributes, it shall be an empty
     *        Attributes object.
     */
    public void startElement(
            StylesheetHandler handler, String uri, String localName, String rawName, Attributes attributes)
              throws org.xml.sax.SAXException
    {
      final String resultNS;
      NamespaceAlias na = new NamespaceAlias(handler.nextUid());
  
      setPropertiesFromAttributes(handler, rawName, attributes, na);
      String prefix = na.getStylesheetPrefix();
      if(prefix.equals("#default"))
      {
        prefix = "";
        na.setStylesheetPrefix(prefix);
      }
      String stylesheetNS = handler.getNamespaceForPrefix(prefix);
      na.setStylesheetNamespace(stylesheetNS);
      prefix = na.getResultPrefix();
      if(prefix.equals("#default"))
      {
        prefix = "";
        na.setResultPrefix(prefix);
        resultNS = handler.getNamespaceForPrefix(prefix);
        if(null == resultNS)
          handler.error(XSLTErrorResources.ER_INVALID_NAMESPACE_URI_VALUE_FOR_RESULT_PREFIX_FOR_DEFAULT, null, null);
      }
      else
      {
          resultNS = handler.getNamespaceForPrefix(prefix);
          if(null == resultNS)
           handler.error(XSLTErrorResources.ER_INVALID_NAMESPACE_URI_VALUE_FOR_RESULT_PREFIX, new Object[] {prefix}, null);
      }
     
      na.setResultNamespace(resultNS);
      handler.getStylesheet().setNamespaceAlias(na);
      handler.getStylesheet().appendChild(na);
    }
  }
  