/*
    * $Id: PutAttributeModel.java 797765 2009-07-25 13:20:26Z apetrelli $
    *
    * 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.tiles.template;
  
  import org.apache.tiles.ArrayStack;
  import org.apache.tiles.Attribute;
  import org.apache.tiles.AttributeContext;
  import org.apache.tiles.Expression;
  import org.apache.tiles.TilesContainer;
  
  /***
   * <p>
   * <strong>Put an attribute in enclosing attribute container tag.</strong>
   * </p>
   * <p>
   * Enclosing attribute container tag can be :
   * <ul>
   * <li>&lt;initContainer&gt;</li>
   * <li>&lt;definition&gt;</li>
   * <li>&lt;insertAttribute&gt;</li>
   * <li>&lt;insertDefinition&gt;</li>
   * <li>&lt;putListAttribute&gt;</li>
   * </ul>
   * (or any other tag which implements the <code>PutAttributeTagParent</code>
   * interface. Exception is thrown if no appropriate tag can be found.
   * </p>
   * <p>
   * Put tag can have following atributes :
   * <ul>
   * <li>name : Name of the attribute</li>
   * <li>value : value to put as attribute</li>
   * <li>type : value type. Possible type are : string (value is used as direct
   * string), template (value is used as a page url to insert), definition (value
   * is used as a definition name to insert), object (value is used as it is)</li>
   * <li>role : Role to check when 'insertAttribute' will be called.</li>
   * </ul>
   * </p>
   * <p>
   * Value can also come from tag body. Tag body is taken into account only if
   * value is not set by one of the tag attributes. In this case Attribute type is
   * "string", unless tag body define another type.
   * </p>
   *
   * @version $Rev: 797765 $ $Date: 2009-07-25 15:20:26 +0200 (sab, 25 lug 2009) $
   * @since 2.2.0
   */
  public class PutAttributeModel {
  
      /***
       * Starts the operation.
       *
       * @param composeStack The compose stack.
       * @since 2.2.0
       */
      public void start(ArrayStack<Object> composeStack) {
          Attribute attribute = new Attribute();
          composeStack.push(attribute);
      }
  
      /***
       * Ends the operation.
       *
       * @param container The Tiles container to use.
       * @param composeStack The composing stack.
       * @param name The name of the attribute to put.
       * @param value The value of the attribute. Use this parameter, or
       * expression, or body.
       * @param expression The expression to calculate the value from. Use this
       * parameter, or value, or body.
       * @param body The body of the tag. Use this parameter, or value, or
       * expression.
       * @param role A comma-separated list of roles. If present, the attribute
       * will be rendered only if the current user belongs to one of the roles.
       * @param type The type (renderer) of the attribute.
       * @param cascade If <code>true</code> the attribute will be cascaded to all nested attributes.
       * @param requestItems The request objects.
       * @since 2.2.0
       */
      public void end(TilesContainer container, ArrayStack<Object> composeStack,
              String name, Object value, String expression, String body,
             String role, String type, boolean cascade, Object... requestItems) {
         Attribute attribute = (Attribute) composeStack.pop();
         putAttributeInParent(attribute, container, composeStack, name, value,
                 expression, body, role, type, cascade, requestItems);
     }
 
     /***
      * Executes the operation.
      *
      * @param container The Tiles container to use.
      * @param composeStack The composing stack.
      * @param name The name of the attribute to put.
      * @param value The value of the attribute. Use this parameter, or
      * expression, or body.
      * @param expression The expression to calculate the value from. Use this
      * parameter, or value, or body.
      * @param body The body of the tag. Use this parameter, or value, or
      * expression.
      * @param role A comma-separated list of roles. If present, the attribute
      * will be rendered only if the current user belongs to one of the roles.
      * @param type The type (renderer) of the attribute.
      * @param cascade If <code>true</code> the attribute will be cascaded to all nested attributes.
      * @param requestItems The request objects.
      * @since 2.2.0
      */
     public void execute(TilesContainer container, ArrayStack<Object> composeStack,
             String name, Object value, String expression, String body,
             String role, String type, boolean cascade, Object... requestItems) {
         putAttributeInParent(new Attribute(), container, composeStack, name,
                 value, expression, body, role, type, cascade, requestItems);
     }
 
     /***
      * Determines the parent and puts the attribute inside it.
      *
      * @param attribute The attribute to put;
      * @param container The Tiles container to use.
      * @param composeStack The composing stack.
      * @param name The name of the attribute to put.
      * @param value The value of the attribute. Use this parameter, or
      * expression, or body.
      * @param expression The expression to calculate the value from. Use this
      * parameter, or value, or body.
      * @param body The body of the tag. Use this parameter, or value, or
      * expression.
      * @param role A comma-separated list of roles. If present, the attribute
      * will be rendered only if the current user belongs to one of the roles.
      * @param type The type (renderer) of the attribute.
      * @param cascade If <code>true</code> the attribute will be cascaded to all nested attributes.
      * @param requestItems The request objects.
      */
     private void putAttributeInParent(Attribute attribute,
             TilesContainer container, ArrayStack<Object> composeStack, String name,
             Object value, String expression, String body, String role,
             String type, boolean cascade, Object... requestItems) {
         AttributeContext attributeContext = null;
         if (!composeStack.isEmpty()) {
             Object obj = composeStack.peek();
             if (obj instanceof AttributeContext) {
                 attributeContext = (AttributeContext) obj;
             }
         }
         if (attributeContext == null) {
             attributeContext = container.getAttributeContext(requestItems);
         }
         if (value != null) {
             attribute.setValue(value);
         } else if (attribute.getValue() == null && body != null) {
             attribute.setValue(body);
         }
         if (expression != null) {
             attribute.setExpressionObject(Expression
                     .createExpressionFromDescribedExpression(expression));
         }
         if (role != null) {
             attribute.setRole(role);
         }
         if (type != null) {
             attribute.setRenderer(type);
         }
 
         attributeContext.putAttribute(name, attribute, cascade);
     }
 }