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Posted to dev@velocity.apache.org by ge...@apache.org on 2002/03/27 16:45:05 UTC

cvs commit: jakarta-velocity/whiteboard/geir Local.java

geirm       02/03/27 07:45:05

  Added:       whiteboard/geir Local.java
  Log:
  give it a whirl...
  
  Revision  Changes    Path
  1.1                  jakarta-velocity/whiteboard/geir/Local.java
  
  Index: Local.java
  ===================================================================
  package org.apache.velocity.runtime.directive;
  
  
  /*
   * The Apache Software License, Version 1.1
   *
   * Copyright (c) 2002 The Apache Software Foundation.  All rights
   * reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   *
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   *
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in
   *    the documentation and/or other materials provided with the
   *    distribution.
   *
   * 3. The end-user documentation included with the redistribution, if
   *    any, must include the following acknowlegement:
   *       "This product includes software developed by the
   *        Apache Software Foundation (http://www.apache.org/)."
   *    Alternately, this acknowlegement may appear in the software itself,
   *    if and wherever such third-party acknowlegements normally appear.
   *
   * 4. The names "The Jakarta Project", "Velocity", and "Apache Software
   *    Foundation" must not be used to endorse or promote products derived
   *    from this software without prior written permission. For written
   *    permission, please contact apache@apache.org.
   *
   * 5. Products derived from this software may not be called "Apache"
   *    nor may "Apache" appear in their names without prior written
   *    permission of the Apache Group.
   *
   * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
   * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
   * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
   * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
   * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
   * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
   * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
   * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
   * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
   * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   * SUCH DAMAGE.
   * ====================================================================
   *
   * This software consists of voluntary contributions made by many
   * individuals on behalf of the Apache Software Foundation.  For more
   * information on the Apache Software Foundation, please see
   * <http://www.apache.org/>.
   */
  
  import org.apache.velocity.runtime.RuntimeServices;
  import org.apache.velocity.runtime.parser.node.Node;
  import org.apache.velocity.runtime.parser.node.ASTReference;
  import org.apache.velocity.runtime.parser.node.SimpleNode;
  import org.apache.velocity.context.InternalContextAdapter;
  import org.apache.velocity.exception.MethodInvocationException;
  import org.apache.velocity.exception.ResourceNotFoundException;
  import org.apache.velocity.exception.ParseErrorException;
  
  import java.io.Writer;
  import java.io.IOException;
  import java.util.ArrayList;
  
  /**
   * Simple implementation of a 'context protector', as desired by
   * Christoph Reck.  Used like
   *
   * #local($a $b $c )
   *  ...
   * #end
   *
   * and restores the value of the reference at the end of the block
   * Assumes that you can #set() the value of any reference in the list
   *
   * @author <a href="mailto:geirm@optonline.net">Geir Magnusson Jr.</a>
   * @version $Id: Local.java,v 1.1 2002/03/27 15:45:05 geirm Exp $
   */
  public class Local extends Directive
  {
      protected Object[] refList;
      protected Node block;
  
      /**
       * Return name of this directive.
       */
      public String getName()
      {
          return "local";
      }
  
      /**
       * Return type of this directive.
       */
      public int getType()
      {
          return BLOCK;
      }
  
      /**
       *
       */
      public void init(RuntimeServices rs, InternalContextAdapter context, Node node)
          throws Exception
      {
          super.init( rs, context, node );
  
          int numchildren = node.jjtGetNumChildren();
  
          ArrayList al = new ArrayList();
  
          /*
           *  get all the references in our arg list
           */
          for (int i=0; i < numchildren-1; i++)
          {
              SimpleNode sn = (SimpleNode) node.jjtGetChild(i);
  
              if (sn instanceof ASTReference )
              {
                  al.add(sn);
              }
              else
              {
                  throw new Exception("Arg " + i + " not a reference.");
              }
          }
  
          refList = al.toArray();
  
          block = node.jjtGetChild(node.jjtGetNumChildren() - 1);
  
      }
  
      /**
       *
       */
      public boolean render(InternalContextAdapter context,
                             Writer writer, Node node)
          throws IOException, ResourceNotFoundException,
              ParseErrorException, MethodInvocationException
      {
  
          /*
           * get the current values for the references we have
           */
  
          ArrayList vals = new ArrayList();
  
          for (int i = 0; i < refList.length; i++)
          {
              Object o = ((ASTReference) refList[i]).value(context);
              vals.add(o);
          }
  
          /*
           *  now render the block
           */
          boolean retVal = block.render(context, writer);
  
          /*
           * now restore the original values
           */
  
          for (int i = 0; i < refList.length; i++)
          {
              ASTReference astr = (ASTReference) refList[i];
              astr.setValue(context, vals.get(i));
          }
  
          return true;
      }
  }
  
  
  

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