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1   /**
2    * This file Copyright (c) 2008-2016 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.rendering.renderer;
35  
36  import info.magnolia.cms.beans.config.MIMEMapping;
37  import info.magnolia.cms.core.AggregationState;
38  import info.magnolia.context.MgnlContext;
39  import info.magnolia.jcr.decoration.ContentDecoratorUtil;
40  import info.magnolia.jcr.util.ContentMap;
41  import info.magnolia.jcr.util.NodeUtil;
42  import info.magnolia.jcr.wrapper.ChannelVisibilityContentDecorator;
43  import info.magnolia.jcr.wrapper.HTMLEscapingNodeWrapper;
44  import info.magnolia.jcr.wrapper.I18nNodeWrapper;
45  import info.magnolia.objectfactory.Components;
46  import info.magnolia.objectfactory.MgnlInstantiationException;
47  import info.magnolia.objectfactory.ParameterInfo;
48  import info.magnolia.objectfactory.ParameterResolver;
49  import info.magnolia.rendering.context.RenderingContext;
50  import info.magnolia.rendering.engine.RenderException;
51  import info.magnolia.rendering.engine.RenderingEngine;
52  import info.magnolia.rendering.model.EarlyExecutionAware;
53  import info.magnolia.rendering.model.ModelExecutionFilter;
54  import info.magnolia.rendering.model.RenderingModel;
55  import info.magnolia.rendering.model.RenderingModelImpl;
56  import info.magnolia.rendering.template.RenderableDefinition;
57  
58  import java.lang.reflect.InvocationTargetException;
59  import java.util.HashMap;
60  import java.util.Map;
61  import java.util.Map.Entry;
62  
63  import javax.inject.Inject;
64  import javax.jcr.Node;
65  import javax.jcr.RepositoryException;
66  import javax.servlet.http.HttpServletResponse;
67  
68  import org.apache.commons.beanutils.BeanUtils;
69  import org.apache.commons.lang3.StringUtils;
70  import org.apache.commons.lang3.exception.ExceptionUtils;
71  
72  /**
73   * Abstract renderer with support for typical functionality such as setting context attributes and executing a
74   * rendering model. Sets up the context by providing the following objects:
75   * <ul>
76   * <li>content</li>
77   * <li>def</li>
78   * <li>state</li>
79   * <li>model</li>
80   * <li>actionResult</li>
81   * </ul>
82   */
83  public abstract class AbstractRenderer implements Renderer, RenderingModelBasedRenderer {
84  
85      protected static final String MODEL_ATTRIBUTE = RenderingModel.class.getName();
86  
87      private Map<String, ContextAttributeConfiguration> contextAttributes = new HashMap<String, ContextAttributeConfiguration>();
88  
89      private RenderingEngine renderingEngine = null;
90  
91      private String contentType;
92  
93      /**
94       * @deprecated since 5.0.2, use {@link #AbstractRenderer(RenderingEngine)}
95       */
96      public AbstractRenderer() {
97          this.renderingEngine = Components.getComponent(RenderingEngine.class);
98      }
99  
100     @Inject
101     public AbstractRenderer(RenderingEngine renderingEngine) {
102         this.renderingEngine = renderingEngine;
103     }
104 
105     @Override
106     public void render(RenderingContext renderingCtx, Map<String, Object> contextObjects) throws RenderException {
107 
108         final RenderingModel<?> parentModel = MgnlContext.getAttribute(MODEL_ATTRIBUTE);
109         Node content = renderingCtx.getCurrentContent();
110         RenderableDefinition definition = renderingCtx.getRenderableDefinition();
111 
112         RenderingModel<?> model = null;
113         String actionResult = null;
114 
115         if (content != null) {
116             String uuid;
117             try {
118                 uuid = content.getIdentifier();
119             } catch (RepositoryException e) {
120                 throw new RenderException(e);
121             }
122 
123             model = MgnlContext.getAttribute(ModelExecutionFilter.MODEL_ATTRIBUTE_PREFIX + uuid);
124             if (model != null) {
125                 actionResult = (String) MgnlContext.getAttribute(ModelExecutionFilter.ACTION_RESULT_ATTRIBUTE_PREFIX + uuid);
126                 if (model instanceof EarlyExecutionAware) {
127                     ((EarlyExecutionAware) model).setParent(parentModel);
128                 }
129             }
130         }
131 
132         if (model == null) {
133             model = newModel(content, definition, parentModel);
134             if (model != null) {
135                 actionResult = model.execute();
136                 if (RenderingModel.SKIP_RENDERING.equals(actionResult)) {
137                     return;
138                 }
139             }
140         }
141 
142         String templatePath = resolveTemplateScript(content, definition, model, actionResult);
143         if (templatePath == null) {
144             throw new RenderException("No template script defined for the template definition [" + definition + "]");
145         }
146 
147         final Map<String, Object> ctx = newContext();
148         final Map<String, Object> savedContextState = saveContextState(ctx);
149         setupContext(ctx, content, definition, model, actionResult);
150         ctx.putAll(contextObjects);
151         MgnlContext.setAttribute(MODEL_ATTRIBUTE, model);
152         content = wrapNodeForModel(content);
153         renderingCtx.push(content, definition);
154         try {
155             final HttpServletResponse response = MgnlContext.getWebContext().getResponse();
156             if (!response.containsHeader("Content-Type")) {
157                 response.setContentType(StringUtils.defaultIfBlank(getContentType(definition), MIMEMapping.getMIMETypeOrDefault(MIMEMapping.DEFAULT_EXTENSION)));
158             }
159 
160             onRender(content, definition, renderingCtx, ctx, templatePath);
161         } finally {
162             renderingCtx.pop();
163         }
164         MgnlContext.setAttribute(MODEL_ATTRIBUTE, parentModel);
165 
166         restoreContext(ctx, savedContextState);
167     }
168 
169     /**
170      * It's currently not possible to determine the content type of the renderer from the {@link RenderableDefinition}.
171      * <code>info.magnolia.module.resources.renderers.ResourcesTextTemplateRenderer</code> is the only renderer making
172      * use of it atm.
173      */
174     protected String getContentType(RenderableDefinition definition) {
175         return this.getContentType();
176     }
177 
178     /**
179      * Hook-method to be overriden when required. Default implementation ignores all arguments except definition.
180      * 
181      * @param definition reference templateScript is retrieved from
182      * @return the templateScript to use
183      */
184     protected String resolveTemplateScript(Node content, RenderableDefinition definition, RenderingModel<?> model, final String actionResult) {
185         return definition.getTemplateScript();
186     }
187 
188     /**
189      * Instantiates the model based on the class defined by the {@link info.magnolia.rendering.template.RenderableDefinition#getModelClass()} property. All the request
190      * parameters are then mapped to the model's properties.
191      */
192     @Override
193     public RenderingModel<?> newModel(final Node content, final RenderableDefinition definition, final RenderingModel<?> parentModel) throws RenderException {
194 
195         Class clazz = definition.getModelClass();
196 
197         // if none is set we default to RenderingModelImpl, so there will always be a model available in templates
198         if (clazz == null) {
199             clazz = RenderingModelImpl.class;
200         }
201 
202         final Node wrappedContent = wrapNodeForModel(content);
203 
204         return newModel(clazz, wrappedContent, definition, parentModel);
205     }
206 
207     protected <T extends RenderingModel<?>> T newModel(Class<T> modelClass, final Node content, final RenderableDefinition definition, final RenderingModel<?> parentModel) throws RenderException {
208 
209         try {
210 
211             T model = Components.getComponentProvider().newInstanceWithParameterResolvers(modelClass,
212                     new ParameterResolver() {
213                         @Override
214                         public Object resolveParameter(ParameterInfo parameter) {
215                             if (parameter.getParameterType().equals(Node.class)) {
216                                 return content;
217                             }
218                             if (parameter.getParameterType().isAssignableFrom(definition.getClass())) {
219                                 return definition;
220                             }
221                             if (parameter.getParameterType().equals(RenderingModel.class)) {
222                                 return parentModel;
223                             }
224                             return UNRESOLVED;
225                         }
226                     }
227                     );
228 
229             // populate the instance with values given as request parameters
230             final boolean autoPopulateFromRequest = definition.getAutoPopulateFromRequest() != null ? definition.getAutoPopulateFromRequest() : renderingEngine.getAutoPopulateFromRequest();
231             if (!autoPopulateFromRequest) {
232                 return model;
233             }
234 
235             Map<String, String[]> params = MgnlContext.getWebContext().getRequest().getParameterMap();
236             if (params == null || params.isEmpty()) {
237                 return model;
238             }
239 
240             // needed workaround to not break rendering when there is no index between square brackets
241             // see https://issues.apache.org/jira/browse/BEANUTILS-419
242             Map<String, Object> filtered = new HashMap<String, Object>();
243             for (Entry<String, String[]> entry : params.entrySet()) {
244                 String key = entry.getKey();
245                 String[] value = entry.getValue();
246                 if (StringUtils.contains(key, "[")) {
247                     key = StringUtils.substringBefore(key, "[");
248                 }
249                 filtered.put(key, value);
250             }
251 
252             BeanUtils.populate(model, filtered);
253 
254             return model;
255 
256         } catch (MgnlInstantiationException e) {
257             throw new RenderException("Can't instantiate model: " + modelClass, e);
258         } catch (InvocationTargetException e) {
259             throw new RenderException("Can't populate rendering model: " + ExceptionUtils.getRootCauseMessage(e), e);
260         } catch (IllegalAccessException e) {
261             throw new RenderException("Can't populate rendering model: " + ExceptionUtils.getRootCauseMessage(e), e);
262         }
263     }
264 
265     protected Map<String, Object> saveContextState(final Map<String, Object> ctx) {
266         Map<String, Object> state = new HashMap<String, Object>();
267         // save former values
268         saveAttribute(ctx, state, "content");
269         saveAttribute(ctx, state, "def");
270         saveAttribute(ctx, state, "state");
271         saveAttribute(ctx, state, "model");
272         saveAttribute(ctx, state, "actionResult");
273 
274         return state;
275     }
276 
277     protected void saveAttribute(final Map<String, Object> ctx, Map<String, Object> state, String name) {
278         state.put(name, ctx.get(name));
279     }
280 
281     protected void restoreContext(final Map<String, Object> ctx, Map<String, Object> state) {
282         for (Entry<String, Object> entry : state.entrySet()) {
283             setContextAttribute(ctx, entry.getKey(), entry.getValue());
284         }
285     }
286 
287     protected void setupContext(final Map<String, Object> ctx, Node content, RenderableDefinition definition, RenderingModel<?> model, Object actionResult) {
288         final Node mainContent = getMainContentSafely(content);
289 
290         setContextAttribute(ctx, "content", content != null ? new ContentMap(wrapNodeForTemplate(content)) : null);
291         setContextAttribute(ctx, "def", definition);
292         setContextAttribute(ctx, "state", getAggregationStateSafely());
293         setContextAttribute(ctx, "model", model);
294         setContextAttribute(ctx, "actionResult", actionResult);
295 
296         for (Entry<String, ContextAttributeConfiguration> entry : contextAttributes.entrySet()) {
297             setContextAttribute(ctx, entry.getKey(), Components.getComponent(entry.getValue().getComponentClass()));
298         }
299 
300     }
301 
302     /**
303      * Gets the current main content or returns null if aggregation state is not set.
304      */
305     protected Node getMainContentSafely(Node content) {
306         AggregationState state = getAggregationStateSafely();
307         return state == null ? content : state.getMainContentNode();
308     }
309 
310     /**
311      * This gets the aggregation state without throwing an exception if the current context is not a WebContext.
312      */
313     protected AggregationState getAggregationStateSafely() {
314         if (MgnlContext.isWebContext()) {
315             return MgnlContext.getAggregationState();
316         }
317         return null;
318     }
319 
320     /**
321      * Wraps the current content node before passing it to the model.
322      * 
323      * @param content the actual content
324      * @return the wrapped content
325      */
326     protected Node wrapNodeForModel(Node content) {
327         NodeUtil.deepUnwrap(content, HTMLEscapingNodeWrapper.class);
328         content = wrapWithChannelVisibilityWrapper(content);
329         content = wrapWithI18NWrapper(content);
330         return content;
331     }
332 
333     /**
334      * Wraps the current content node for exposing it to the template script as a context attribute.
335      * 
336      * @param content the actual content
337      * @return the wrapped content
338      */
339     protected Node wrapNodeForTemplate(Node content) {
340         content = wrapWithChannelVisibilityWrapper(content);
341         content = wrapWithI18NWrapper(content);
342         content = wrapWithHTMLEscapingWrapper(content);
343         return content;
344     }
345 
346     private Node wrapWithHTMLEscapingWrapper(Node content) {
347         if (!NodeUtil.isWrappedWith(content, HTMLEscapingNodeWrapper.class)) {
348             content = new HTMLEscapingNodeWrapper(content, true);
349         }
350         return content;
351     }
352 
353     private Node wrapWithI18NWrapper(Node content) {
354         if (!NodeUtil.isWrappedWith(content, I18nNodeWrapper.class)) {
355             content = new I18nNodeWrapper(content);
356         }
357         return content;
358     }
359 
360     private Node wrapWithChannelVisibilityWrapper(Node content) {
361         // If it's already wrapped then we don't need to add a new one
362         if (ContentDecoratorUtil.isDecoratedWith(content, ChannelVisibilityContentDecorator.class)) {
363             return content;
364         }
365         AggregationState aggregationState = getAggregationStateSafely();
366         if (aggregationState == null) {
367             return content;
368         }
369         String channel = aggregationState.getChannel().getName();
370         if (StringUtils.isEmpty(channel) || channel.equalsIgnoreCase("all")) {
371             return content;
372         }
373         return new ChannelVisibilityContentDecorator(channel).wrapNode(content);
374     }
375 
376     protected Object setContextAttribute(final Map<String, Object> ctx, final String name, Object value) {
377         return ctx.put(name, value);
378     }
379 
380     public Map<String, ContextAttributeConfiguration> getContextAttributes() {
381         return contextAttributes;
382     }
383 
384     public void setContextAttributes(Map<String, ContextAttributeConfiguration> contextAttributes) {
385         if (this.contextAttributes != null) {
386             this.contextAttributes.putAll(contextAttributes);
387         } else {
388             this.contextAttributes = contextAttributes;
389         }
390     }
391 
392     public void addContextAttribute(String name, ContextAttributeConfiguration contextAttributeConfiguration) {
393         this.contextAttributes.put(name, contextAttributeConfiguration);
394     }
395 
396     /**
397      * Create a new context object which is a map.
398      */
399     protected abstract Map<String, Object> newContext();
400 
401     /**
402      * Finally execute the rendering.
403      */
404     protected abstract void onRender(Node content, RenderableDefinition definition, RenderingContext renderingCtx, Map<String, Object> ctx, String templateScript) throws RenderException;
405 
406     public String getContentType() {
407         return contentType;
408     }
409 
410     public void setContentType(String contentType) {
411         this.contentType = contentType;
412     }
413 }