org.argeo.slc.core/src/org/argeo/slc/core/execution/generator/ExecutionFlowGenerator.java

   1 /*
   2  * Copyright (C) 2007-2012 Argeo GmbH
   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 package org.argeo.slc.core.execution.generator;
  17
  18 import java.util.HashMap;
  19
  20 import org.apache.commons.logging.Log;
  21 import org.apache.commons.logging.LogFactory;
  22 import org.argeo.slc.SlcException;
  23 import org.springframework.aop.scope.ScopedProxyUtils;
  24 import org.springframework.beans.BeansException;
  25 import org.springframework.beans.MutablePropertyValues;
  26 import org.springframework.beans.factory.config.BeanDefinitionHolder;
  27 import org.springframework.beans.factory.config.BeanFactoryPostProcessor;
  28 import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
  29 import org.springframework.beans.factory.config.RuntimeBeanReference;
  30 import org.springframework.beans.factory.support.BeanDefinitionRegistry;
  31 import org.springframework.beans.factory.support.GenericBeanDefinition;
  32 import org.springframework.core.Ordered;
  33
  34 /**
  35  * Generates <code>ExecutionFlows</code> and <code>Runnables</code> as
  36  * beans in the Spring Application Context.
  37  * Called by the Application Context as a <code>BeanFactoryPostProcessor</code>.
  38  * Two kinds of beans are generated:
  39  * <code>RunnableCallFlow</code>, calling a list of <code>Runnables</code> from the
  40  * Application Context after configuring the <code>ExecutionContext</code>,
  41  * and outputs of a <code>RunnableFactory</code>.
  42  */
  43 public class ExecutionFlowGenerator implements BeanFactoryPostProcessor,
  44                 Ordered {
  45
  46         private final Log log = LogFactory.getLog(getClass());
  47
  48         /**
  49          * Source providing a list of <code>RunnableCallFlowDescriptor</code>
  50          * used to create <code>RunnableCallFlow</code> and a list of
  51          * <code>RunnableDataNode</code> used to create any kind of flow via a factory
  52          */
  53         protected ExecutionFlowGeneratorSource source;
  54
  55         /**
  56          * Factory used to create Runnables in the Application context from
  57          * the <code>RunnableDataNode</code> provided from the source.
  58          */
  59         protected RunnableFactory runnableFactory;
  60
  61         /**
  62          * Bean name of the <code>ExecutionContext</code>.
  63          * Used to provide the created <code>RunnableCallFlow</code> beans
  64          * with a <code>RuntimeBeanReference</code> to
  65          * the <code>ExecutionContext</code>
  66          */
  67         private String executionContextBeanName = "executionContext";
  68
  69         /**
  70          * Bean name of the context values Map.
  71          * A bean of class HashMap is created with this name, and a
  72          * <code>RuntimeBeanReference</code> is provided to the created
  73          * <code>RunnableCallFlow</code> beans.
  74          */
  75         private String contextValuesBeanName = "executionFlowGenerator.contextValues";
  76
  77         /**
  78          * Prefix added to the bean names defined in each
  79          * <code>RunnableCallFlowDescriptor</code>
  80          */
  81         private String flowBeanNamesPrefix = "";
  82
  83         private int order = Ordered.HIGHEST_PRECEDENCE;
  84
  85         public void postProcessBeanFactory(
  86                         ConfigurableListableBeanFactory beanFactory) throws BeansException {
  87
  88                 // assert that the beanFactory is a BeanDefinitionRegistry
  89                 if (!(beanFactory instanceof BeanDefinitionRegistry)) {
  90                         throw new SlcException("Can only work on "
  91                                         + BeanDefinitionRegistry.class);
  92                 }
  93
  94                 // add bean for the Context Values Map
  95                 createAndRegisterContextValuesBean((BeanDefinitionRegistry) beanFactory);
  96
  97                 // add beans for each RunnableDataNode
  98                 for(RunnableDataNode node : source.getRunnableDataNodes()) {
  99                         runnableFactory.createAndRegisterRunnable(node, (BeanDefinitionRegistry) beanFactory);
 100                 }
 101
 102                 // add beans for each RunnableCallFlowDescriptor of the source to the application context
 103                 for (RunnableCallFlowDescriptor descriptor : source
 104                                 .getRunnableCallFlowDescriptors()) {
 105                         createAndRegisterFlowFor(descriptor, (BeanDefinitionRegistry) beanFactory);
 106                 }
 107         }
 108
 109         /**
 110          * Creates a <code>RunnableCallFlow</code> bean
 111          * for a <code>RunnableCallFlowDescriptor</code> and registers
 112          * it in the <code>BeanDefinitionRegistry</code>
 113          * @param flowDescriptor
 114          * @param registry
 115          */
 116         private void createAndRegisterFlowFor(RunnableCallFlowDescriptor flowDescriptor, BeanDefinitionRegistry registry) {
 117                 // create the flow bean
 118                 GenericBeanDefinition flowBean = new GenericBeanDefinition();
 119                 flowBean.setBeanClass(RunnableCallFlow.class);
 120
 121                 String beanName = flowBeanNamesPrefix + flowDescriptor.getBeanName();
 122
 123                 MutablePropertyValues mpv = new MutablePropertyValues();
 124                 mpv.addPropertyValue("runnableCalls", flowDescriptor.getRunnableCalls());
 125                 mpv.addPropertyValue("sharedContextValuesMap", new RuntimeBeanReference(contextValuesBeanName));
 126
 127                 mpv.addPropertyValue("name", beanName);
 128                 mpv.addPropertyValue("path", flowDescriptor.getPath());
 129
 130                 mpv.addPropertyValue("executionContext", new RuntimeBeanReference(executionContextBeanName));
 131
 132                 flowBean.setPropertyValues(mpv);
 133
 134                 // register it
 135                 if(log.isDebugEnabled()) {
 136                         log.debug("Registering bean definition for RunnableCallFlow " + beanName);
 137                 }
 138                 registry.registerBeanDefinition(beanName, flowBean);
 139         }
 140
 141         /**
 142          * Creates the Context Values bean and register it in the
 143          * <code>BeanDefinitionRegistry</code>
 144          * @param registry
 145          */
 146         private void createAndRegisterContextValuesBean(BeanDefinitionRegistry registry) {
 147                 GenericBeanDefinition contextValuesBean = new GenericBeanDefinition();
 148                 contextValuesBean.setBeanClass(HashMap.class);
 149
 150                 BeanDefinitionHolder bdh = ScopedProxyUtils.createScopedProxy(new BeanDefinitionHolder(contextValuesBean, contextValuesBeanName), registry, true);
 151                 registry.registerBeanDefinition(contextValuesBeanName, bdh.getBeanDefinition());
 152         }
 153
 154         public int getOrder() {
 155                 return order;
 156         }
 157
 158         public void setOrder(int order) {
 159                 this.order = order;
 160         }
 161
 162         public void setSource(ExecutionFlowGeneratorSource source) {
 163                 this.source = source;
 164         }
 165
 166         public void setRunnableFactory(RunnableFactory runnableFactory) {
 167                 this.runnableFactory = runnableFactory;
 168         }
 169
 170         public void setExecutionContextBeanName(String executionContextBeanName) {
 171                 this.executionContextBeanName = executionContextBeanName;
 172         }
 173
 174         public void setContextValuesBeanName(String contextValuesBeanName) {
 175                 this.contextValuesBeanName = contextValuesBeanName;
 176         }
 177
 178         public void setFlowBeanNamesPrefix(String flowBeanNamesPrefix) {
 179                 this.flowBeanNamesPrefix = flowBeanNamesPrefix;
 180         }
 181 }