addtag.java

structs源码

/*
 * $Id: AddTag.java 471754 2006-11-06 14:55:09Z husted $
 *
 * 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.
 */


package org.apache.struts.tiles.taglib;

import javax.servlet.jsp.JspException;

  /**
   * Add an element to the surrounding list tag.
   * Same syntax as <code>&lt;put&gt;</code>.
   */
public class AddTag extends PutTag {

  /**
   * default constructor
   */
  public AddTag() {
    super();
  }

    /**
     * Call parent tag which must implement AttributeContainer.
     * @throws JspException If we can't find an appropriate enclosing tag.
     */
  protected void callParent() throws JspException
    {
            // Get enclosing parent
    AddTagParent enclosingParent = findEnclosingPutListTagParent();
    enclosingParent.processNestedTag( this );
    }

    /**
     * Find parent tag which must implement AttributeContainer.
     * @throws JspException If we can't find an appropriate enclosing tag.
     */
  protected AddTagParent findEnclosingPutListTagParent() throws JspException {
    try
      {
      AddTagParent parent = (AddTagParent)findAncestorWithClass(this,AddTagParent.class);
      if( parent == null )
        {
        throw new JspException( "Error - tag add : enclosing tag doesn't accept 'add' tag." );
        }
      return parent;
      }
     catch( ClassCastException ex )
      {
      throw new JspException( "Error - tag add : enclosing tag doesn't accept 'add' tag." , ex);
      }
  }
}