/*

  * $Id: PutAttributeModel.java 1305937 2012-03-27 18:15:15Z nlebas $

  *

  * 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 java.io.IOException;

 import java.util.Deque;

 import org.apache.tiles.Attribute;

 import org.apache.tiles.AttributeContext;

 import org.apache.tiles.Expression;

 import org.apache.tiles.TilesContainer;

 import org.apache.tiles.access.TilesAccess;

 import org.apache.tiles.autotag.core.runtime.ModelBody;

 import org.apache.tiles.autotag.core.runtime.annotation.Parameter;

 import org.apache.tiles.request.Request;

 /**

  * <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: 1305937 $ $Date: 2012-03-28 05:15:15 +1100 (Wed, 28 Mar 2012) $

  * @since 2.2.0

  */

 public class PutAttributeModel {

     /**

      * Executes the operation.

      * @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 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 request The request.

      * @param modelBody The body.

      * @throws IOException If the body cannot be evaluated.

      * @since 2.2.0

      */

     public void execute(@Parameter(required = true) String name, Object value,

             String expression, String role, String type, boolean cascade,

             Request request, ModelBody modelBody) throws IOException {

         Deque<Object> composeStack = ComposeStackUtil.getComposeStack(request);

         Attribute attribute = new Attribute();

         composeStack.push(attribute);

         String currentBody = modelBody.evaluateAsString();

         TilesContainer container = TilesAccess.getCurrentContainer(request);

         attribute = (Attribute) composeStack.pop();

         putAttributeInParent(attribute, container, composeStack, name,

                 value, expression, currentBody, role, type, cascade, request);

     }

     /**

      * 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 request The request.

      */

     private void putAttributeInParent(Attribute attribute,

             TilesContainer container, Deque<Object> composeStack, String name,

             Object value, String expression, String body, String role,

             String type, boolean cascade, Request request) {

         AttributeContext attributeContext = null;

         if (!composeStack.isEmpty()) {

             Object obj = composeStack.peek();

             if (obj instanceof AttributeContext) {

                 attributeContext = (AttributeContext) obj;

             }

         }

         if (attributeContext == null) {

             attributeContext = container.getAttributeContext(request);

         }

         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);

     }

 }