/*

  * $Id: DefinitionModel.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.Definition;

 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.mgmt.MutableTilesContainer;

 import org.apache.tiles.request.Request;

 /**

  * <p>

  * <strong>Create a definition at runtime. </strong>

  * </p>

  * <p>

  * Create a new definition at runtime. Newly created definition will be

  * available across the entire request.

  * </p>

  *

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

  * @since 2.2.0

  */

 public class DefinitionModel {

     /**

      * Executes the operation.

      *

      * @param name The name of the definition to create. If not specified, an

      * anonymous definition will be created.

      * @param template The template of this definition.

      * @param role A comma-separated list of roles. If present, the definition

      * will be rendered only if the current user belongs to one of the roles.

      * @param extendsParam The definition name that this definition extends.

      * @param preparer The preparer to use to invoke before the definition is

      * rendered.

      * @param request The request.

      * @param modelBody The body.

      * @throws IOException If something goes wrong.

      * @since 2.2.0

      */

     public void execute(String name, String template, String role,

             @Parameter(name = "extends") String extendsParam, String preparer,

             Request request, ModelBody modelBody) throws IOException {

         Deque<Object> composeStack = ComposeStackUtil

                 .getComposeStack(request);

         Definition definition = createDefinition(name, template, role,

                 extendsParam, preparer);

         composeStack.push(definition);

         modelBody.evaluateWithoutWriting();

         MutableTilesContainer container = (MutableTilesContainer) TilesAccess

                 .getCurrentContainer(request);

         definition = (Definition) composeStack.pop();

         registerDefinition(definition, container, composeStack, request);

     }

     /**

      * Creates the definition to store.

      *

      * @param name The name of the definition to create. If not specified, an

      * anonymous definition will be created.

      * @param template The template of this definition.

      * @param role A comma-separated list of roles. If present, the definition

      * will be rendered only if the current user belongs to one of the roles.

      * @param extendsParam The definition name that this definition extends.

      * @param preparer The preparer to use to invoke before the definition is

      * rendered.

      * @return The created definition.

      */

     private Definition createDefinition(String name, String template,

             String role, String extendsParam, String preparer) {

         Definition definition = new Definition();

         definition.setName(name);

         Attribute templateAttribute = Attribute

                 .createTemplateAttribute(template);

         templateAttribute.setRole(role);

         definition.setTemplateAttribute(templateAttribute);

         definition.setExtends(extendsParam);

         definition.setPreparer(preparer);

         return definition;

     }

     /**

      * Registers a definition in the container.

      *

      * @param definition The definition to register.

      * @param container The container into which the definition will be

      * registered.

      * @param composeStack The compose stack,

      * @param request The request.

      */

     private void registerDefinition(Definition definition,

             MutableTilesContainer container, Deque<Object> composeStack,

             Request request) {

         container.register(definition, request);

         if (composeStack.isEmpty()) {

             return;

         }

         Object obj = composeStack.peek();

         if (obj instanceof Attribute) {

             Attribute attribute = (Attribute) obj;

             attribute.setValue(definition.getName());

             if (attribute.getRenderer() == null) {

                 attribute.setRenderer("definition");

             }

         }

     }

 }