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1   /**
2    * This file Copyright (c) 2003-2018 Magnolia International
3    * Ltd.  (http://www.magnolia-cms.com). All rights reserved.
4    *
5    *
6    * This file is dual-licensed under both the Magnolia
7    * Network Agreement and the GNU General Public License.
8    * You may elect to use one or the other of these licenses.
9    *
10   * This file is distributed in the hope that it will be
11   * useful, but AS-IS and WITHOUT ANY WARRANTY; without even the
12   * implied warranty of MERCHANTABILITY or FITNESS FOR A
13   * PARTICULAR PURPOSE, TITLE, or NONINFRINGEMENT.
14   * Redistribution, except as permitted by whichever of the GPL
15   * or MNA you select, is prohibited.
16   *
17   * 1. For the GPL license (GPL), you can redistribute and/or
18   * modify this file under the terms of the GNU General
19   * Public License, Version 3, as published by the Free Software
20   * Foundation.  You should have received a copy of the GNU
21   * General Public License, Version 3 along with this program;
22   * if not, write to the Free Software Foundation, Inc., 51
23   * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
24   *
25   * 2. For the Magnolia Network Agreement (MNA), this file
26   * and the accompanying materials are made available under the
27   * terms of the MNA which accompanies this distribution, and
28   * is available at http://www.magnolia-cms.com/mna.html
29   *
30   * Any modifications to this file must keep this entire header
31   * intact.
32   *
33   */
34  package info.magnolia.freemarker.models;
35  
36  import info.magnolia.freemarker.FreemarkerConfig;
37  
38  import java.util.ArrayList;
39  import java.util.List;
40  
41  import freemarker.ext.util.ModelFactory;
42  import freemarker.template.Configuration;
43  import freemarker.template.DefaultObjectWrapper;
44  import freemarker.template.TemplateModel;
45  import freemarker.template.TemplateModelException;
46  
47  /**
48   * A FreeMarker ObjectWrapper that knows about Magnolia specific objects.
49   */
50  public class MagnoliaObjectWrapper extends DefaultObjectWrapper {
51      private final static org.slf4j.Logger log = org.slf4j.LoggerFactory.getLogger(MagnoliaObjectWrapper.class);
52  
53      private final static List<MagnoliaModelFactory> DEFAULT_MODEL_FACTORIES = new ArrayList<MagnoliaModelFactory>() {{
54          add(ContentMapModel.FACTORY);
55          add(CalendarModel.FACTORY);
56          add(UserModel.FACTORY);
57          add(ContextModelFactory.INSTANCE);
58      }};
59  
60      private final FreemarkerConfig freemarkerConfig;
61  
62      public MagnoliaObjectWrapper(FreemarkerConfig freemarkerConfig) {
63          super(Configuration.VERSION_2_3_28);
64          this.freemarkerConfig = freemarkerConfig;
65      }
66  
67      @Override
68      public TemplateModel wrap(Object obj) throws TemplateModelException {
69  
70          if (obj == null) {
71              return super.wrap(null);
72          }
73  
74          // wrap enums
75          // can't do this later, as the Class instance passed to getModelFactory() lost the information about its enum.
76          if ((obj instanceof Class) && ((Class) obj).isEnum()) {
77              final String enumClassName = ((Class) obj).getName();
78              return getEnumModels().get(enumClassName);
79          }
80  
81          // We let our own model factories have precedence over freemarker defaults, typically used to prevent classes
82          // implementing Map or Collection from being wrapped as SimpleHash and SimpleSequence. We intentionally don't
83          // consider model factories created in the super class method getModelFactory(Class) here because that would
84          // side step default wrapping in super.wrap(Object). I.e. the model factory returned for Map is a MapModel
85          // instead of SimpleHash returned by super.wrap(Object).
86          Class<?> clazz = obj.getClass();
87          ModelFactory modelFactory = getModelFactory(clazz, freemarkerConfig.getModelFactories());
88          if (modelFactory == null) {
89              modelFactory = getModelFactory(clazz, DEFAULT_MODEL_FACTORIES);
90          }
91          if (modelFactory != null) {
92              return handleUnknownType(obj);
93          }
94  
95          return super.wrap(obj);
96      }
97  
98      /**
99       * Checks the ModelFactory instances registered in FreemarkerConfig, then
100      * the default ones. If no appropriate ModelFactory was found, delegates to
101      * Freemarker's implementation. This is called by {@link freemarker.ext.beans.BeansModelCache},
102      * which is itself called by {@link freemarker.ext.beans.BeansWrapper#wrap}.
103      * These factories are cached by Freemarker, so this method only gets called
104      * once per type of object.
105      *
106      * @see #DEFAULT_MODEL_FACTORIES
107      * @see info.magnolia.freemarker.FreemarkerConfig
108      */
109     @Override
110     protected ModelFactory getModelFactory(Class clazz) {
111         final List<MagnoliaModelFactory> registeredModelFactories = freemarkerConfig.getModelFactories();
112         ModelFactory modelFactory = getModelFactory(clazz, registeredModelFactories);
113 
114         if (modelFactory == null) {
115             modelFactory = getModelFactory(clazz, DEFAULT_MODEL_FACTORIES);
116         }
117         if (modelFactory == null) {
118             modelFactory = super.getModelFactory(clazz);
119         }
120         return modelFactory;
121     }
122 
123     private ModelFactory getModelFactory(Class clazz, List<MagnoliaModelFactory> factories) {
124         for (MagnoliaModelFactory factory : factories) {
125             if (factory.factoryFor().isAssignableFrom(clazz)) {
126                 return factory;
127             }
128         }
129         return null;
130     }
131 }