/*
    * $Id: PutListTag.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 java.util.ArrayList;
  import java.util.List;
  
  import javax.servlet.jsp.JspException;
  import javax.servlet.jsp.tagext.TagSupport;
  
  import org.apache.struts.tiles.AttributeDefinition;
  import org.apache.struts.tiles.UntypedAttribute;
  
  /**
   * PutList tag implementation.
   */
  public class PutListTag
      extends TagSupport
      implements ComponentConstants, AddTagParent, PutListTagParent {
  
      /**
       * Name of this attribute.
       */
      private String attributeName = null;
  
      /**
       * The list itself.
       */
      private List list = null;
  
      /**
       * Role attribute.
       */
      private String role = null;
  
      /**
       * Default constructor.
       */
      public PutListTag() {
          super();
      }
  
      /**
       * Release all allocated resources.
       */
      public void release() {
          super.release();
          attributeName = null;
          role = null;
      }
  
      /**
       * Release all internal resources.
       */
      protected void releaseInternal() {
          list = null;
      }
  
      /**
       * Set property.
       */
      public void setName(String name) {
          this.attributeName = name;
      }
  
      /**
       * Get property.
       */
      public String getName() {
          return attributeName;
      }
  
      /**
       * Set role attribute.
       * @param role The role the user must be in to store content.
       */
      public void setRole(String role) {
          this.role = role;
      }
  
     /**
      * Get role attribute.
      */
     public String getRole() {
         return role;
     }
 
     /**
      * Get list defined in tag.
      */
     public List getList() {
         return list;
     }
 
     /**
      * Set property.
      */
     public void addElement(Object value) {
         if (list == null) {
             list = new ArrayList();
         }
 
         list.add(value);
     }
 
     /**
      * Process nested ≶putList> tag.
      * Method calls by nested ≶putList> tags.
      * Nested list is added to current list.
      * If role is defined, nested attribute is wrapped into an untypped definition
      * containing attribute value and role.
      */
     public void processNestedTag(PutListTag nestedTag) throws JspException {
         // Get real value and check role
         // If role is set, add it in attribute definition if any.
         // If no attribute definition, create untyped one, and set role.
         Object attributeValue = nestedTag.getList();
 
         if (nestedTag.getRole() != null) {
             AttributeDefinition def = new UntypedAttribute(attributeValue);
             def.setRole(nestedTag.getRole());
             attributeValue = def;
         }
 
         // now add attribute to enclosing parent (i.e. : this object)
         addElement(attributeValue);
     }
 
     /**
      * Process nested ≶add> tag.
      * Method calls by nested ≶add> tags.
      * Nested attribute is added to current list.
      * If role is defined, nested attribute is wrapped into an untypped definition
      * containing attribute value and role.
      */
     public void processNestedTag(AddTag nestedTag) throws JspException {
         // Get real value and check role
         // If role is set, add it in attribute definition if any.
         // If no attribute definition, create untyped one, and set role.
         Object attributeValue = nestedTag.getRealValue();
         AttributeDefinition def;
 
         if (nestedTag.getRole() != null) {
             try {
                 def = ((AttributeDefinition) attributeValue);
             } catch (ClassCastException ex) {
                 def = new UntypedAttribute(attributeValue);
             }
             def.setRole(nestedTag.getRole());
             attributeValue = def;
         }
 
         // now add attribute to enclosing parent (i.e. : this object)
         addElement(attributeValue);
     }
 
     /**
      * Do start tag.
      */
     public int doStartTag() throws JspException {
         return EVAL_BODY_INCLUDE;
     }
 
     /**
      * Do end tag.
      */
     public int doEndTag() throws JspException {
         PutListTagParent enclosingParent = findEnclosingParent();
         enclosingParent.processNestedTag(this);
         // Clear list to avoid reuse
         releaseInternal();
         return EVAL_PAGE;
     }
 
     /**
      * Find enclosing parent tag accepting this tag.
      * @throws JspException If we can't find an appropriate enclosing tag.
      */
     protected PutListTagParent findEnclosingParent() throws JspException {
         try {
             PutListTagParent parent =
                 (PutListTagParent) findAncestorWithClass(this,
                     PutListTagParent.class);
 
             if (parent == null) {
                 throw new JspException("Error - tag putList : enclosing tag doesn't accept 'putList' tag.");
             }
 
             return parent;
 
         } catch (ClassCastException ex) {
             throw new JspException("Error - tag putList : enclosing tag doesn't accept 'putList' tag.", ex);
         }
     }
 
 }