spring/SpringExtensionFactory.java

   1 /*
   2  * Copyright (C) 2010 Mathieu Baudier <mbaudier@argeo.org>
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  *         http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16
  17 package org.argeo.eclipse.spring;
  18
  19 import org.eclipse.core.runtime.CoreException;
  20 import org.eclipse.core.runtime.IConfigurationElement;
  21 import org.eclipse.core.runtime.IExecutableExtension;
  22 import org.eclipse.core.runtime.IExecutableExtensionFactory;
  23 import org.eclipse.core.runtime.IExtension;
  24 import org.springframework.context.ApplicationContext;
  25
  26 /**
  27  * The Spring Extension Factory builds a bridge between the Eclipse Extension
  28  * Registry and the Spring Framework (especially Spring Dynamic Modules).
  29  *
  30  * It allows you to define your extension as a spring bean within the spring
  31  * application context of your bundle. If you would like to use this bean as an
  32  * instance of an extension (an Eclipse RCP view, for example) you define the
  33  * extension with this spring extension factory as the class to be created.
  34  *
  35  * To let the spring extension factory pick the right bean from your application
  36  * context you need to set the bean id to the same value as the id of the view
  37  * within the view definition, for example. This is important if your extension
  38  * definition contains more than one element, where each element has its own id.
  39  *
  40  * If the extension definition elements themselves have no id attribute the
  41  * spring extension factory uses the id of the extension itself to identify the
  42  * bean.
  43  *
  44  * original code from: <a href="http://martinlippert.blogspot.com/2008/10/new-version-of-spring-extension-factory.html"
  45  * >Blog entry</a>
  46  *
  47  * @author Martin Lippert
  48  * @author mbaudier
  49  */
  50 public class SpringExtensionFactory implements IExecutableExtensionFactory,
  51                 IExecutableExtension {
  52
  53         private Object bean;
  54
  55         public Object create() throws CoreException {
  56                 return bean;
  57         }
  58
  59         public void setInitializationData(IConfigurationElement config,
  60                         String propertyName, Object data) throws CoreException {
  61                 String beanName = getBeanName(data, config);
  62                 ApplicationContext appContext = ApplicationContextTracker
  63                                 .getApplicationContext(config.getContributor().getName());
  64
  65                 if (beanName != null && appContext != null) {
  66                         this.bean = appContext.getBean(beanName);
  67                         if (this.bean instanceof IExecutableExtension) {
  68                                 ((IExecutableExtension) this.bean).setInitializationData(
  69                                                 config, propertyName, data);
  70                         }
  71                 }
  72         }
  73
  74         private String getBeanName(Object data, IConfigurationElement config) {
  75
  76                 // try the specific bean id the extension defines
  77                 if (data != null && data.toString().length() > 0) {
  78                         return data.toString();
  79                 }
  80
  81                 // try the id of the config element
  82                 if (config.getAttribute("id") != null) {
  83                         return config.getAttribute("id");
  84                 }
  85
  86                 // try the id of the extension element itself
  87                 if (config.getParent() != null
  88                                 && config.getParent() instanceof IExtension) {
  89                         IExtension extensionDefinition = (IExtension) config.getParent();
  90                         return extensionDefinition.getSimpleIdentifier();
  91                 }
  92
  93                 return null;
  94         }
  95
  96 }