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1   /**
2    * This file Copyright (c) 2010-2016 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.TemplateNumberModel;
46  import freemarker.template.TemplateScalarModel;
47  import freemarker.template.TemplateSequenceModel;
48  import freemarker.template.utility.DeepUnwrap;
49  
50  import info.magnolia.cms.core.Content;
51  import info.magnolia.freemarker.models.ContentMapModel;
52  import info.magnolia.freemarker.models.ContentModel;
53  import info.magnolia.objectfactory.Components;
54  import info.magnolia.rendering.context.RenderingContext;
55  import info.magnolia.rendering.engine.RenderException;
56  import info.magnolia.rendering.engine.RenderingEngine;
57  import info.magnolia.templating.elements.AbstractContentTemplatingElement;
58  import info.magnolia.templating.elements.TemplatingElement;
59  
60  import java.io.IOException;
61  import java.lang.reflect.ParameterizedType;
62  import java.util.ArrayList;
63  import java.util.Collections;
64  import java.util.List;
65  import java.util.Map;
66  
67  import javax.jcr.Node;
68  
69  /**
70   * A base class for freemarker directives used in Magnolia.
71   *
72   * @param <C> the templating element the directive is operating on
73   */
74  public abstract class AbstractDirective<C extends TemplatingElement> implements TemplateDirectiveModel {
75  
76      public static final String PATH_ATTRIBUTE = "path";
77      public static final String UUID_ATTRIBUTE = "uuid";
78      public static final String WORKSPACE_ATTRIBUTE = "workspace";
79      public static final String CONTENT_ATTRIBUTE = "content";
80  
81      @Override
82      public void execute(Environment env, Map params, TemplateModel[] loopVars, TemplateDirectiveBody body) throws TemplateException, IOException {
83  
84          final C templatingElement = createTemplatingElement();
85  
86          prepareTemplatingElement(templatingElement, env, params, loopVars, body);
87  
88          // prepareTemplatingElement should have removed the parameters it knows about.
89          if (!params.isEmpty()) {
90              throw new TemplateModelException("Unsupported parameter(s): " + params);
91          }
92  
93          try {
94              templatingElement.begin(env.getOut());
95  
96              try {
97                  doBody(env, body);
98              } finally {
99                  templatingElement.end(env.getOut());
100             }
101         } catch (RenderException e) {
102             throw new TemplateException(e, env);
103         }
104     }
105 
106     protected C createTemplatingElement() {
107 
108         // FIXME use scope instead of fetching the RenderingContext for passing it as an argument
109         final RenderingEngine renderingEngine = Components.getComponent(RenderingEngine.class);
110         final RenderingContext renderingContext = renderingEngine.getRenderingContext();
111 
112         return Components.getComponentProvider().newInstance(getTemplatingElementClass(), renderingContext);
113     }
114 
115     protected Class<C> getTemplatingElementClass() {
116         // TODO does this support more than one level of subclasses?
117         return (Class<C>) ((ParameterizedType) this.getClass().getGenericSuperclass()).getActualTypeArguments()[0];
118     }
119 
120     /**
121      * Implementations of this method should prepare the TemplatingElement with the known parameters.
122      * If parameters have been grabbed using the methods provided by this class, they should be removed from
123      * 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)}
124      * will throw a TemplateModelException if there are leftover parameters.
125      * <p/>
126      * <strong>note:</strong> The current FreeMarker implementation passes a "new" Map which we can safely manipulate.
127      * is thrown away after the execution of the directive. When no parameters are passed, the Map is readonly, but it
128      * is otherwise a regular HashMap which has been instantiated shortly before the execution of the directive. However, since
129      * this behavior is not mandated by their API, nor documented (at the time of writing, with FreeMarker 2.3.16), we
130      * should exert caution. Unit tests hopefully cover this, so we'll be safe when updating to newer FreeMarker versions.
131      */
132     protected abstract void prepareTemplatingElement(C templatingElement, Environment env, Map<String, TemplateModel> params, TemplateModel[] loopVars, TemplateDirectiveBody body) throws TemplateModelException, IOException;
133 
134     protected void doBody(Environment env, TemplateDirectiveBody body) throws TemplateException, IOException {
135         if (body != null) {
136             body.render(env.getOut());
137         }
138     }
139 
140     /**
141      * Utility method for directives who need to ensure they're used with or without a body.
142      * If the body is *optional*, this method shouldn't be used.
143      */
144     protected void checkBody(TemplateDirectiveBody body, boolean needsBody) throws TemplateModelException {
145         if ((body == null) == needsBody) {
146             throw new TemplateModelException("This directive " + (needsBody ? "needs a body" : "does not support a body"));
147         }
148     }
149 
150     protected String mandatoryString(Map<String, TemplateModel> params, String key) throws TemplateModelException {
151         return _param(params, key, TemplateScalarModel.class, true).getAsString();
152     }
153 
154     protected String string(Map<String, TemplateModel> params, String key, String defaultValue) throws TemplateModelException {
155         final TemplateScalarModel m = _param(params, key, TemplateScalarModel.class, false);
156         if (m == null) { // we've already checked if the param is mandatory already
157             return defaultValue;
158         }
159         return m.getAsString();
160     }
161 
162     protected boolean mandatoryBool(Map<String, TemplateModel> params, String key) throws TemplateModelException {
163         return _param(params, key, TemplateBooleanModel.class, true).getAsBoolean();
164     }
165 
166     protected Boolean bool(Map<String, TemplateModel> params, String key, Boolean defaultValue) throws TemplateModelException {
167         final TemplateBooleanModel m = _param(params, key, TemplateBooleanModel.class, false);
168         if (m == null) {
169             return defaultValue;
170         }
171         return m.getAsBoolean();
172     }
173 
174     protected Integer integer(Map<String, TemplateModel> params, String key, Integer defaultValue) throws TemplateModelException {
175         final TemplateNumberModel m = _param(params, key, TemplateNumberModel.class, false);
176         if (m == null) {
177             return defaultValue;
178         }
179         return m.getAsNumber().intValue();
180     }
181 
182     @Deprecated
183     protected Content mandatoryContent(Map<String, TemplateModel> params, String key) throws TemplateModelException {
184         return _param(params, key, ContentModel.class, true).asContent();
185     }
186 
187     @Deprecated
188     protected Content content(Map<String, TemplateModel> params, String key, Content defaultValue) throws TemplateModelException {
189         final ContentModel m = _param(params, key, ContentModel.class, false);
190         if (m == null) {
191             return defaultValue;
192         }
193         return m.asContent();
194     }
195 
196     protected Node node(Map<String, TemplateModel> params, String key, Node defaultValue) throws TemplateModelException {
197         final ContentMapModel m = _param(params, key, ContentMapModel.class, false);
198         if (m == null) {
199             return defaultValue;
200         }
201         return m.getJCRNode();
202     }
203 
204     protected Object object(Map<String, TemplateModel> params, String key) throws TemplateModelException {
205         final TemplateModel model = _param(params, key, TemplateModel.class, false);
206         if (model == null) {
207             return null;
208         }
209         return DeepUnwrap.unwrap(model);
210     }
211 
212     protected Object mandatoryObject(Map<String, TemplateModel> params, String key) throws TemplateModelException {
213         final TemplateModel model = _param(params, key, TemplateModel.class, true);
214         return DeepUnwrap.unwrap(model);
215     }
216 
217     protected List<String> mandatoryStringList(Map<String, TemplateModel> params, String key) throws TemplateModelException {
218         final TemplateModel model = _param(params, key, TemplateModel.class, true);
219         if (model instanceof TemplateScalarModel) {
220             final String s = ((TemplateScalarModel) model).getAsString();
221             return Collections.singletonList(s);
222         } else if (model instanceof TemplateSequenceModel) {
223             final CollectionAndSequence coll = new CollectionAndSequence((TemplateSequenceModel) model);
224             return unwrapStringList(coll, key);
225         } else if (model instanceof TemplateCollectionModel) {
226             final CollectionAndSequence coll = new CollectionAndSequence((TemplateCollectionModel) model);
227             return unwrapStringList(coll, key);
228         } else {
229             throw new TemplateModelException(key + " must be a String, a Collection of Strings. Found " + model.getClass().getSimpleName() + ".");
230         }
231     }
232 
233     private List<String> unwrapStringList(CollectionAndSequence collAndSeq, String key) throws TemplateModelException {
234         final List<String> list = new ArrayList<String>();
235         for (int i = 0; i < collAndSeq.size(); i++) {
236             final TemplateModel tm = collAndSeq.get(i);
237             if (tm instanceof TemplateScalarModel) {
238                 list.add(((TemplateScalarModel) tm).getAsString());
239             } else {
240                 throw new TemplateModelException("The '" + key + "' attribute must be a String or a Collection of Strings. Found Collection of " + tm.getClass().getSimpleName() + ".");
241             }
242         }
243         return list;
244     }
245 
246     protected <MT extends TemplateModel> MT _param(Map<String, TemplateModel> params, String key, Class<MT> type, boolean isMandatory) throws TemplateModelException {
247         final boolean containsKey = params.containsKey(key);
248         if (isMandatory && !containsKey) {
249             throw new TemplateModelException("The '" + key + "' parameter is mandatory.");
250 
251         }
252         // can't remove here: in case of parameter-less directive call, FreeMarker passes a read-only Map.
253         final TemplateModel m = params.get(key);
254         if (m != null && !type.isAssignableFrom(m.getClass())) {
255             throw new TemplateModelException("The '" + key + "' parameter must be a " + type.getSimpleName() + " and is a " + m.getClass().getSimpleName() + ".");
256         }
257         if (m == null && containsKey) {
258             // parameter is passed but null value ... (happens with content.nonExistingSubNode apparently)
259             throw new TemplateModelException("The '" + key + "' parameter was passed but not or wrongly specified.");
260         }
261         if (containsKey) {
262             params.remove(key);
263         }
264 
265         return (MT) m;
266     }
267 
268     /**
269      * Init attributes common to all {@link AbstractContentTemplatingElement}.
270      */
271     protected void initContentElement(Map<String, TemplateModel> params, AbstractContentTemplatingElement component) throws TemplateModelException {
272         Node content = node(params, CONTENT_ATTRIBUTE, null);
273         String workspace = string(params, WORKSPACE_ATTRIBUTE, null);
274         String nodeIdentifier = string(params, UUID_ATTRIBUTE, null);
275         String path = string(params, PATH_ATTRIBUTE, null);
276 
277         component.setContent(content);
278         component.setWorkspace(workspace);
279         component.setNodeIdentifier(nodeIdentifier);
280         component.setPath(path);
281     }
282 }