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1   /*
2    * $Id: PutAttributeModel.java 1305937 2012-03-27 18:15:15Z nlebas $
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  import java.util.Deque;
26  
27  import org.apache.tiles.Attribute;
28  import org.apache.tiles.AttributeContext;
29  import org.apache.tiles.Expression;
30  import org.apache.tiles.TilesContainer;
31  import org.apache.tiles.access.TilesAccess;
32  import org.apache.tiles.autotag.core.runtime.ModelBody;
33  import org.apache.tiles.autotag.core.runtime.annotation.Parameter;
34  import org.apache.tiles.request.Request;
35  
36  /**
37   * <p>
38   * <strong>Put an attribute in enclosing attribute container tag.</strong>
39   * </p>
40   * <p>
41   * Enclosing attribute container tag can be :
42   * <ul>
43   * <li>&lt;initContainer&gt;</li>
44   * <li>&lt;definition&gt;</li>
45   * <li>&lt;insertAttribute&gt;</li>
46   * <li>&lt;insertDefinition&gt;</li>
47   * <li>&lt;putListAttribute&gt;</li>
48   * </ul>
49   * (or any other tag which implements the <code>PutAttributeTagParent</code>
50   * interface. Exception is thrown if no appropriate tag can be found.
51   * </p>
52   * <p>
53   * Put tag can have following atributes :
54   * <ul>
55   * <li>name : Name of the attribute</li>
56   * <li>value : value to put as attribute</li>
57   * <li>type : value type. Possible type are : string (value is used as direct
58   * string), template (value is used as a page url to insert), definition (value
59   * is used as a definition name to insert), object (value is used as it is)</li>
60   * <li>role : Role to check when 'insertAttribute' will be called.</li>
61   * </ul>
62   * </p>
63   * <p>
64   * Value can also come from tag body. Tag body is taken into account only if
65   * value is not set by one of the tag attributes. In this case Attribute type is
66   * "string", unless tag body define another type.
67   * </p>
68   *
69   * @version $Rev: 1305937 $ $Date: 2012-03-28 05:15:15 +1100 (Wed, 28 Mar 2012) $
70   * @since 2.2.0
71   */
72  public class PutAttributeModel {
73  
74      /**
75       * Executes the operation.
76       * @param name The name of the attribute to put.
77       * @param value The value of the attribute. Use this parameter, or
78       * expression, or body.
79       * @param expression The expression to calculate the value from. Use this
80       * parameter, or value, or body.
81       * @param role A comma-separated list of roles. If present, the attribute
82       * will be rendered only if the current user belongs to one of the roles.
83       * @param type The type (renderer) of the attribute.
84       * @param cascade If <code>true</code> the attribute will be cascaded to all nested attributes.
85       * @param request The request.
86       * @param modelBody The body.
87       * @throws IOException If the body cannot be evaluated.
88       * @since 2.2.0
89       */
90      public void execute(@Parameter(required = true) String name, Object value,
91              String expression, String role, String type, boolean cascade,
92              Request request, ModelBody modelBody) throws IOException {
93          Deque<Object> composeStack = ComposeStackUtil.getComposeStack(request);
94          Attribute attribute = new Attribute();
95          composeStack.push(attribute);
96          String currentBody = modelBody.evaluateAsString();
97          TilesContainer container = TilesAccess.getCurrentContainer(request);
98          attribute = (Attribute) composeStack.pop();
99          putAttributeInParent(attribute, container, composeStack, name,
100                 value, expression, currentBody, role, type, cascade, request);
101     }
102 
103     /**
104      * Determines the parent and puts the attribute inside it.
105      *
106      * @param attribute The attribute to put;
107      * @param container The Tiles container to use.
108      * @param composeStack The composing stack.
109      * @param name The name of the attribute to put.
110      * @param value The value of the attribute. Use this parameter, or
111      * expression, or body.
112      * @param expression The expression to calculate the value from. Use this
113      * parameter, or value, or body.
114      * @param body The body of the tag. Use this parameter, or value, or
115      * expression.
116      * @param role A comma-separated list of roles. If present, the attribute
117      * will be rendered only if the current user belongs to one of the roles.
118      * @param type The type (renderer) of the attribute.
119      * @param cascade If <code>true</code> the attribute will be cascaded to all nested attributes.
120      * @param request The request.
121      */
122     private void putAttributeInParent(Attribute attribute,
123             TilesContainer container, Deque<Object> composeStack, String name,
124             Object value, String expression, String body, String role,
125             String type, boolean cascade, Request request) {
126         AttributeContext attributeContext = null;
127         if (!composeStack.isEmpty()) {
128             Object obj = composeStack.peek();
129             if (obj instanceof AttributeContext) {
130                 attributeContext = (AttributeContext) obj;
131             }
132         }
133         if (attributeContext == null) {
134             attributeContext = container.getAttributeContext(request);
135         }
136         if (value != null) {
137             attribute.setValue(value);
138         } else if (attribute.getValue() == null && body != null) {
139             attribute.setValue(body);
140         }
141         if (expression != null) {
142             attribute.setExpressionObject(Expression
143                     .createExpressionFromDescribedExpression(expression));
144         }
145         if (role != null) {
146             attribute.setRole(role);
147         }
148         if (type != null) {
149             attribute.setRenderer(type);
150         }
151 
152         attributeContext.putAttribute(name, attribute, cascade);
153     }
154 }