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1   /*
2    * $Id: InsertTemplateModel.java 1058106 2011-01-12 12:22:58Z apetrelli $
3    *
4    * Licensed to the Apache Software Foundation (ASF) under one
5    * or more contributor license agreements.  See the NOTICE file
6    * distributed with this work for additional information
7    * regarding copyright ownership.  The ASF licenses this file
8    * to you under the Apache License, Version 2.0 (the
9    * "License"); you may not use this file except in compliance
10   * with the License.  You may obtain a copy of the License at
11   *
12   * http://www.apache.org/licenses/LICENSE-2.0
13   *
14   * Unless required by applicable law or agreed to in writing,
15   * software distributed under the License is distributed on an
16   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17   * KIND, either express or implied.  See the License for the
18   * specific language governing permissions and limitations
19   * under the License.
20   */
21  
22  package org.apache.tiles.template;
23  
24  import java.io.IOException;
25  
26  import org.apache.tiles.Attribute;
27  import org.apache.tiles.AttributeContext;
28  import org.apache.tiles.TilesContainer;
29  import org.apache.tiles.access.TilesAccess;
30  import org.apache.tiles.autotag.core.runtime.ModelBody;
31  import org.apache.tiles.autotag.core.runtime.annotation.Parameter;
32  import org.apache.tiles.request.Request;
33  
34  /**
35   * <p>
36   * <strong>Insert a template.</strong>
37   * </p>
38   * <p>
39   * Insert a template with the possibility to pass parameters (called
40   * attributes). A template can be seen as a procedure that can take parameters
41   * or attributes. <code>&lt;tiles:insertTemplate&gt;</code> allows to define
42   * these attributes and pass them to the inserted jsp page, called template.
43   * Attributes are defined using nested tag
44   * <code>&lt;tiles:putAttribute&gt;</code> or
45   * <code>&lt;tiles:putListAttribute&gt;</code>.
46   * </p>
47   * <p>
48   * You must specify <code>template</code> attribute, for inserting a template
49   * </p>
50   *
51   * <p>
52   * <strong>Example : </strong>
53   * </p>
54   *
55   * <pre>
56   * &lt;code&gt;
57   *           &lt;tiles:insertTemplate template=&quot;/basic/myLayout.jsp&quot; flush=&quot;true&quot;&gt;
58   *              &lt;tiles:putAttribute name=&quot;title&quot; value=&quot;My first page&quot; /&gt;
59   *              &lt;tiles:putAttribute name=&quot;header&quot; value=&quot;/common/header.jsp&quot; /&gt;
60   *              &lt;tiles:putAttribute name=&quot;footer&quot; value=&quot;/common/footer.jsp&quot; /&gt;
61   *              &lt;tiles:putAttribute name=&quot;menu&quot; value=&quot;/basic/menu.jsp&quot; /&gt;
62   *              &lt;tiles:putAttribute name=&quot;body&quot; value=&quot;/basic/helloBody.jsp&quot; /&gt;
63   *           &lt;/tiles:insertTemplate&gt;
64   *         &lt;/code&gt;
65   * </pre>
66   *
67   * @version $Rev: 1058106 $ $Date: 2011-01-12 23:22:58 +1100 (Wed, 12 Jan 2011) $
68   * @since 2.2.0
69   */
70  public class InsertTemplateModel {
71  
72      /**
73       * Executes the operation.
74       * @param template The template to render.
75       * @param templateType The type of the template attribute.
76       * @param templateExpression The expression to evaluate to get the value of the template.
77       * @param role A comma-separated list of roles. If present, the template
78       * will be rendered only if the current user belongs to one of the roles.
79       * @param preparer The preparer to use to invoke before the definition is
80       * rendered. If specified, it overrides the preparer specified in the
81       * definition itself.
82       * @param flush If <code>true</code>, the response will be flushed after the insert.
83       * @param request The request.
84       * @param modelBody The body.
85       * @throws IOException If something goes wrong.
86       * @since 2.2.0
87       */
88      public void execute(@Parameter(required = true) String template,
89              String templateType, String templateExpression, String role,
90              String preparer, boolean flush, Request request, ModelBody modelBody)
91              throws IOException {
92          TilesContainer container = TilesAccess.getCurrentContainer(request);
93          container.startContext(request);
94          modelBody.evaluateWithoutWriting();
95          container = TilesAccess.getCurrentContainer(request);
96          renderTemplate(container, template, templateType, templateExpression,
97                  role, preparer, flush, request);
98      }
99  
100     /**
101      * Renders a template.
102      *
103      * @param container The container to use.
104      * @param template The template to render.
105      * @param templateType The type of the template attribute.
106      * @param templateExpression The expression to evaluate to get the value of the template.
107      * @param role A comma-separated list of roles. If present, the template
108      * will be rendered only if the current user belongs to one of the roles.
109      * @param preparer The preparer to use to invoke before the definition is
110      * rendered. If specified, it overrides the preparer specified in the
111      * definition itself.
112      * @param flush If <code>true</code>, the response will be flushed after the insert.
113      * @param request The request.
114      * @throws IOException If something goes wrong.
115      */
116     private void renderTemplate(TilesContainer container, String template,
117             String templateType, String templateExpression, String role,
118             String preparer, boolean flush, Request request) throws IOException {
119         try {
120             AttributeContext attributeContext = container
121                     .getAttributeContext(request);
122             Attribute templateAttribute = Attribute.createTemplateAttribute(template,
123                     templateExpression, templateType, role);
124             attributeContext.setPreparer(preparer);
125             attributeContext.setTemplateAttribute(templateAttribute);
126             container.renderContext(request);
127             if (flush) {
128                 request.getWriter().flush();
129             }
130         } finally {
131             container.endContext(request);
132         }
133     }
134 }