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1   /**
2    * This file Copyright (c) 2010-2015 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.templating.freemarker;
35  
36  import freemarker.core.CollectionAndSequence;
37  import freemarker.core.Environment;
38  import freemarker.template.TemplateBooleanModel;
39  import freemarker.template.TemplateCollectionModel;
40  import freemarker.template.TemplateDirectiveBody;
41  import freemarker.template.TemplateDirectiveModel;
42  import freemarker.template.TemplateException;
43  import freemarker.template.TemplateModel;
44  import freemarker.template.TemplateModelException;
45  import freemarker.template.TemplateScalarModel;
46  import freemarker.template.TemplateSequenceModel;
47  import freemarker.template.utility.DeepUnwrap;
48  import info.magnolia.cms.core.Content;
49  import info.magnolia.freemarker.models.ContentMapModel;
50  import info.magnolia.freemarker.models.ContentModel;
51  import info.magnolia.objectfactory.Components;
52  import info.magnolia.rendering.context.RenderingContext;
53  import info.magnolia.rendering.engine.RenderException;
54  import info.magnolia.rendering.engine.RenderingEngine;
55  import info.magnolia.templating.elements.AbstractContentTemplatingElement;
56  import info.magnolia.templating.elements.TemplatingElement;
57  
58  import java.io.IOException;
59  import java.lang.reflect.ParameterizedType;
60  import java.util.ArrayList;
61  import java.util.Collections;
62  import java.util.List;
63  import java.util.Map;
64  
65  import javax.jcr.Node;
66  
67  /**
68   * A base class for freemarker directives used in Magnolia.
69   *
70   * @param <C> the templating element the directive is operating on
71   */
72  public abstract class AbstractDirective<C extends TemplatingElement> implements TemplateDirectiveModel {
73  
74      public static final String PATH_ATTRIBUTE = "path";
75      public static final String UUID_ATTRIBUTE = "uuid";
76      public static final String WORKSPACE_ATTRIBUTE = "workspace";
77      public static final String CONTENT_ATTRIBUTE = "content";
78  
79      @Override
80      public void execute(Environment env, Map params, TemplateModel[] loopVars, TemplateDirectiveBody body) throws TemplateException, IOException {
81  
82          final C templatingElement = createTemplatingElement();
83  
84          prepareTemplatingElement(templatingElement, env, params, loopVars, body);
85  
86          // prepareTemplatingElement should have removed the parameters it knows about.
87          if (!params.isEmpty()) {
88              throw new TemplateModelException("Unsupported parameter(s): " + params);
89          }
90  
91          try {
92              templatingElement.begin(env.getOut());
93  
94              try {
95                  doBody(env, body);
96              } finally {
97                  templatingElement.end(env.getOut());
98              }
99          } catch (RenderException e) {
100             throw new TemplateException(e, env);
101         }
102     }
103 
104     protected C createTemplatingElement() {
105 
106         // FIXME use scope instead of fetching the RenderingContext for passing it as an argument
107         final RenderingEngine renderingEngine = Components.getComponent(RenderingEngine.class);
108         final RenderingContext renderingContext = renderingEngine.getRenderingContext();
109 
110         return Components.getComponentProvider().newInstance(getTemplatingElementClass(), renderingContext);
111     }
112 
113     protected Class<C> getTemplatingElementClass() {
114         // TODO does this support more than one level of subclasses?
115         return (Class<C>) ((ParameterizedType) this.getClass().getGenericSuperclass()).getActualTypeArguments()[0];
116     }
117 
118     /**
119      * Implementations of this method should prepare the TemplatingElement with the known parameters.
120      * If parameters have been grabbed using the methods provided by this class, they should be removed from
121      * the map, thus leaving an empty map once the method returns. {@link #execute(freemarker.core.Environment, java.util.Map, freemarker.template.TemplateModel[], freemarker.template.TemplateDirectiveBody)}
122      * will throw a TemplateModelException if there are leftover parameters.
123      * <p/>
124      * <strong>note:</strong> The current FreeMarker implementation passes a "new" Map which we can safely manipulate.
125      * is thrown away after the execution of the directive. When no parameters are passed, the Map is readonly, but it
126      * is otherwise a regular HashMap which has been instantiated shortly before the execution of the directive. However, since
127      * this behavior is not mandated by their API, nor documented (at the time of writing, with FreeMarker 2.3.16), we
128      * should exert caution. Unit tests hopefully cover this, so we'll be safe when updating to newer FreeMarker versions.
129      */
130     protected abstract void prepareTemplatingElement(C templatingElement, Environment env, Map<String, TemplateModel> params, TemplateModel[] loopVars, TemplateDirectiveBody body) throws TemplateModelException, IOException;
131 
132     protected void doBody(Environment env, TemplateDirectiveBody body) throws TemplateException, IOException {
133         if (body != null) {
134             body.render(env.getOut());
135         }
136     }
137 
138     /**
139      * Utility method for directives who need to ensure they're used with or without a body.
140      * If the body is *optional*, this method shouldn't be used.
141      */
142     protected void checkBody(TemplateDirectiveBody body, boolean needsBody) throws TemplateModelException {
143         if ((body == null) == needsBody) {
144             throw new TemplateModelException("This directive " + (needsBody ? "needs a body" : "does not support a body"));
145         }
146     }
147 
148     protected String mandatoryString(Map<String, TemplateModel> params, String key) throws TemplateModelException {
149         return _param(params, key, TemplateScalarModel.class, true).getAsString();
150     }
151 
152     protected String string(Map<String, TemplateModel> params, String key, String defaultValue) throws TemplateModelException {
153         final TemplateScalarModel m = _param(params, key, TemplateScalarModel.class, false);
154         if (m == null) { // we've already checked if the param is mandatory already
155             return defaultValue;
156         }
157         return m.getAsString();
158     }
159 
160     protected boolean mandatoryBool(Map<String, TemplateModel> params, String key) throws TemplateModelException {
161         return _param(params, key, TemplateBooleanModel.class, true).getAsBoolean();
162     }
163 
164     protected Boolean bool(Map<String, TemplateModel> params, String key, Boolean defaultValue) throws TemplateModelException {
165         final TemplateBooleanModel m = _param(params, key, TemplateBooleanModel.class, false);
166         if (m == null) {
167             return defaultValue;
168         }
169         return m.getAsBoolean();
170     }
171 
172     @Deprecated
173     protected Content mandatoryContent(Map<String, TemplateModel> params, String key) throws TemplateModelException {
174         return _param(params, key, ContentModel.class, true).asContent();
175     }
176 
177     @Deprecated
178     protected Content content(Map<String, TemplateModel> params, String key, Content defaultValue) throws TemplateModelException {
179         final ContentModel m = _param(params, key, ContentModel.class, false);
180         if (m == null) {
181             return defaultValue;
182         }
183         return m.asContent();
184     }
185 
186     protected Node node(Map<String, TemplateModel> params, String key, Node defaultValue) throws TemplateModelException {
187         final ContentMapModel m = _param(params, key, ContentMapModel.class, false);
188         if (m == null) {
189             return defaultValue;
190         }
191         return m.getJCRNode();
192     }
193 
194     protected Object object(Map<String, TemplateModel> params, String key) throws TemplateModelException {
195         final TemplateModel model = _param(params, key, TemplateModel.class, false);
196         if (model == null) {
197             return null;
198         }
199         return DeepUnwrap.unwrap(model);
200     }
201 
202     protected Object mandatoryObject(Map<String, TemplateModel> params, String key) throws TemplateModelException {
203         final TemplateModel model = _param(params, key, TemplateModel.class, true);
204         return DeepUnwrap.unwrap(model);
205     }
206 
207     protected List<String> mandatoryStringList(Map<String, TemplateModel> params, String key) throws TemplateModelException {
208         final TemplateModel model = _param(params, key, TemplateModel.class, true);
209         if (model instanceof TemplateScalarModel) {
210             final String s = ((TemplateScalarModel) model).getAsString();
211             return Collections.singletonList(s);
212         } else if (model instanceof TemplateSequenceModel) {
213             final CollectionAndSequence coll = new CollectionAndSequence((TemplateSequenceModel) model);
214             return unwrapStringList(coll, key);
215         } else if (model instanceof TemplateCollectionModel) {
216             final CollectionAndSequence coll = new CollectionAndSequence((TemplateCollectionModel) model);
217             return unwrapStringList(coll, key);
218         } else {
219             throw new TemplateModelException(key + " must be a String, a Collection of Strings. Found " + model.getClass().getSimpleName() + ".");
220         }
221     }
222 
223     private List<String> unwrapStringList(CollectionAndSequence collAndSeq, String key) throws TemplateModelException {
224         final List<String> list = new ArrayList<String>();
225         for (int i = 0; i < collAndSeq.size(); i++) {
226             final TemplateModel tm = collAndSeq.get(i);
227             if (tm instanceof TemplateScalarModel) {
228                 list.add(((TemplateScalarModel) tm).getAsString());
229             } else {
230                 throw new TemplateModelException("The '" + key + "' attribute must be a String or a Collection of Strings. Found Collection of " + tm.getClass().getSimpleName() + ".");
231             }
232         }
233         return list;
234     }
235 
236     protected <MT extends TemplateModel> MT _param(Map<String, TemplateModel> params, String key, Class<MT> type, boolean isMandatory) throws TemplateModelException {
237         final boolean containsKey = params.containsKey(key);
238         if (isMandatory && !containsKey) {
239             throw new TemplateModelException("The '" + key + "' parameter is mandatory.");
240 
241         }
242         // can't remove here: in case of parameter-less directive call, FreeMarker passes a read-only Map.
243         final TemplateModel m = params.get(key);
244         if (m != null && !type.isAssignableFrom(m.getClass())) {
245             throw new TemplateModelException("The '" + key + "' parameter must be a " + type.getSimpleName() + " and is a " + m.getClass().getSimpleName() + ".");
246         }
247         if (m == null && containsKey) {
248             // parameter is passed but null value ... (happens with content.nonExistingSubNode apparently)
249             throw new TemplateModelException("The '" + key + "' parameter was passed but not or wrongly specified.");
250         }
251         if (containsKey) {
252             params.remove(key);
253         }
254 
255         return (MT) m;
256     }
257 
258     /**
259      * Init attributes common to all {@link AbstractContentTemplatingElement}.
260      */
261     protected void initContentElement(Map<String, TemplateModel> params, AbstractContentTemplatingElement component) throws TemplateModelException {
262         Node content = node(params, CONTENT_ATTRIBUTE, null);
263         String workspace = string(params, WORKSPACE_ATTRIBUTE, null);
264         String nodeIdentifier = string(params, UUID_ATTRIBUTE, null);
265         String path = string(params, PATH_ATTRIBUTE, null);
266 
267         component.setContent(content);
268         component.setWorkspace(workspace);
269         component.setNodeIdentifier(nodeIdentifier);
270         component.setPath(path);
271     }
272 }