cvs commit: cocoon-2.1/src/blocks/scratchpad/java/org/apache/cocoon/environment TemplateObjectModelHelper.java

[cz...@apache.org]

cziegeler    2004/04/01 03:54:52

  Added:       src/blocks/scratchpad/java/org/apache/cocoon/environment
                        TemplateObjectModelHelper.java
  Log:
  First version of a common template object model
  
  Revision  Changes    Path
  1.1                  cocoon-2.1/src/blocks/scratchpad/java/org/apache/cocoon/environment/TemplateObjectModelHelper.java
  
  Index: TemplateObjectModelHelper.java
  ===================================================================
  /*
   * Copyright 1999-2004 The Apache Software Foundation.
   * 
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   * 
   *      http://www.apache.org/licenses/LICENSE-2.0
   * 
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package org.apache.cocoon.environment;
  
  import java.beans.PropertyDescriptor;
  import java.lang.reflect.Method;
  import java.util.HashMap;
  import java.util.Map;
  
  import org.apache.avalon.framework.parameters.Parameters;
  import org.apache.cocoon.components.flow.FlowHelper;
  import org.apache.commons.jxpath.DynamicPropertyHandler;
  import org.apache.commons.jxpath.JXPathBeanInfo;
  import org.apache.commons.jxpath.JXPathIntrospector;
  
  
  /**
   * This is an utility class to create an object model which is similar to the one
   * used in flow, that can be used from every component.
   * 
   * Work-in-progress, derived from JXTemplateGenerator
   * 
   * @version CVS $Id: TemplateObjectModelHelper.java,v 1.1 2004/04/01 11:54:52 cziegeler Exp $
   */
  public class TemplateObjectModelHelper {
  
      /** Avoid instantiation */
      private TemplateObjectModelHelper() {}
  
      private static void fillContext(Object contextObject, Map map) {
          // Hack: I use jxpath to populate the context object's properties
          // in the jexl context
          final JXPathBeanInfo bi =
              JXPathIntrospector.getBeanInfo(contextObject.getClass());
          if (bi.isDynamic()) {
              Class cl = bi.getDynamicPropertyHandlerClass();
              try {
                  DynamicPropertyHandler h =
                      (DynamicPropertyHandler) cl.newInstance();
                  String[] result = h.getPropertyNames(contextObject);
                  int len = result.length;
                  for (int i = 0; i < len; i++) {
                      try {
                          map.put(result[i], h.getProperty(contextObject, result[i]));
                      } catch (Exception exc) {
                          exc.printStackTrace();
                      }
                  }
              } catch (Exception ignored) {
                  ignored.printStackTrace();
              }
          } else {
              PropertyDescriptor[] props =  bi.getPropertyDescriptors();
              int len = props.length;
              for (int i = 0; i < len; i++) {
                  try {
                      Method read = props[i].getReadMethod();
                      if (read != null) {
                          map.put(props[i].getName(),
                                  read.invoke(contextObject, null));
                      }
                  } catch (Exception ignored) {
                      ignored.printStackTrace();
                  }
              }
          }
      }
  
      /**
       * Create the object model.
       * Currently the object model is a map with one single entry:
       *  cocoon + request         The Request Object
       *         + session         The Session (if available)
       *         + context         The Context
       *         + continuation    The Continuation (if available)
       *         + parameters      The parameters (if provided)
       */
      public static Object getTemplateObjectModel(final Map objectModel, 
                                                  final Parameters parameters) {
  
          // first create the "cocoon object":
          final Map cocoon = new HashMap();
          
          // cocoon.request
          final Request request = ObjectModelHelper.getRequest( objectModel );
          cocoon.put("request", request);
          
          // cocoon.session
          final Session session = request.getSession(false);
          if (session != null) {
              cocoon.put("session", session);
          }
          
          // cocoon.context
          cocoon.put("context", ObjectModelHelper.getContext(objectModel));
          
          // cocoon.continuation
          final Object cont = FlowHelper.getWebContinuation(objectModel);
          if ( cont != null ) {
              cocoon.put("continuation", cont);
          }
          
          // cocoon.parameters
          if ( parameters != null ) {
              cocoon.put("parameters", Parameters.toProperties(parameters));
          }
  
          final Map map = new HashMap();
          map.put("cocoon", cocoon);
  
          // Now add objects from flow context (if any)
          final Object contextObject = FlowHelper.getContextObject(objectModel);
          if (contextObject instanceof Map) {
              map.putAll((Map)contextObject);
          } else if ( contextObject != null ) {
              fillContext(contextObject, map);
          }
          
          return map;
      }
  
  }