runtime/org.argeo.slc.core/src/main/java/org/argeo/slc/core/execution/xml/FlowBeanDefinitionParser.java

   1 /*
   2  * Copyright (C) 2007-2012 Mathieu Baudier
   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.xml;
  17
  18 import java.util.ArrayList;
  19 import java.util.List;
  20
  21 import org.apache.commons.logging.Log;
  22 import org.apache.commons.logging.LogFactory;
  23 import org.argeo.slc.SlcException;
  24 import org.argeo.slc.core.execution.DefaultExecutionFlow;
  25 import org.argeo.slc.execution.ExecutionFlow;
  26 import org.springframework.beans.factory.BeanDefinitionStoreException;
  27 import org.springframework.beans.factory.config.RuntimeBeanReference;
  28 import org.springframework.beans.factory.support.AbstractBeanDefinition;
  29 import org.springframework.beans.factory.support.BeanDefinitionBuilder;
  30 import org.springframework.beans.factory.support.ManagedList;
  31 import org.springframework.beans.factory.support.ManagedMap;
  32 import org.springframework.beans.factory.xml.AbstractSingleBeanDefinitionParser;
  33 import org.springframework.beans.factory.xml.ParserContext;
  34 import org.springframework.util.StringUtils;
  35 import org.springframework.util.xml.DomUtils;
  36 import org.w3c.dom.Element;
  37 import org.w3c.dom.Node;
  38 import org.w3c.dom.NodeList;
  39
  40 /** Interprets the <flow:flow> tag */
  41 public class FlowBeanDefinitionParser extends
  42                 AbstractSingleBeanDefinitionParser {
  43         private Log log = LogFactory.getLog(FlowBeanDefinitionParser.class);
  44
  45         @SuppressWarnings("unchecked")
  46         @Override
  47         protected void doParse(Element element, ParserContext parserContext,
  48                         BeanDefinitionBuilder builder) {
  49                 String path = element.getAttribute("path");
  50                 if (StringUtils.hasText(path))
  51                         log.warn("The 'path' attribute is not used anymore to build flows");
  52
  53                 String spec = element.getAttribute("spec");
  54                 if (StringUtils.hasText(spec))
  55                         builder.getBeanDefinition().getConstructorArgumentValues()
  56                                         .addGenericArgumentValue(new RuntimeBeanReference(spec));
  57
  58                 String abstrac = element.getAttribute("abstract");
  59                 if (StringUtils.hasText(abstrac))
  60                         builder.setAbstract(Boolean.parseBoolean(abstrac));
  61
  62                 String parent = element.getAttribute("parent");
  63                 if (StringUtils.hasText(parent))
  64                         builder.setParentName(parent);
  65
  66                 builder.getBeanDefinition().setDescription(
  67                                 DomUtils.getChildElementValueByTagName(element, "description"));
  68
  69                 List<Element> argsElems = new ArrayList<Element>();
  70                 List<Element> execElems = new ArrayList<Element>();
  71                 List<Element> specElems = new ArrayList<Element>();
  72                 NodeList nodeList = element.getChildNodes();
  73                 for (int i = 0; i < nodeList.getLength(); i++) {
  74                         Node node = nodeList.item(i);
  75                         if (node instanceof Element) {
  76                                 if (DomUtils.nodeNameEquals(node, "arg"))
  77                                         argsElems.add((Element) node);
  78                                 else if (DomUtils.nodeNameEquals(node, "spec"))
  79                                         specElems.add((Element) node);
  80                                 else if (!DomUtils.nodeNameEquals(node, "description"))
  81                                         execElems.add((Element) node);
  82                         }
  83                 }
  84
  85                 // Arguments
  86                 if (argsElems.size() != 0) {
  87                         ManagedMap args = new ManagedMap(argsElems.size());
  88                         for (Element argElem : argsElems) {
  89                                 Object value = NamespaceUtils.parseValue(argElem,
  90                                                 parserContext, builder.getBeanDefinition(), null);
  91                                 if (value != null)
  92                                         args.put(argElem.getAttribute("name"), value);
  93                                 else
  94                                         throw new SlcException("No value defined.");
  95                         }
  96                         builder.getBeanDefinition().getConstructorArgumentValues()
  97                                         .addGenericArgumentValue(args);
  98                 }
  99
 100                 // Execution specs
 101                 if (StringUtils.hasText(spec) && specElems.size() != 0)
 102                         throw new SlcException("A flow cannot have multiple specs");
 103                 if (specElems.size() == 1) {
 104                         Object specObj = NamespaceUtils.parseBeanOrReference(
 105                                         specElems.get(0), parserContext,
 106                                         builder.getBeanDefinition());
 107                         builder.getBeanDefinition().getConstructorArgumentValues()
 108                                         .addGenericArgumentValue(specObj);
 109                 } else if (specElems.size() > 1)
 110                         throw new SlcException("A flow cannot have multiple specs");
 111
 112                 // Executables
 113                 if (execElems.size() != 0) {
 114                         ManagedList executables = new ManagedList(execElems.size());
 115                         for (Element child : execElems) {
 116                                 // child validity check is performed in xsd
 117                                 executables.add(NamespaceUtils.parseBeanOrReference(child,
 118                                                 parserContext, builder.getBeanDefinition()));
 119                         }
 120                         if (executables.size() > 0)
 121                                 builder.addPropertyValue("executables", executables);
 122                 }
 123         }
 124
 125         @SuppressWarnings("unchecked")
 126         @Override
 127         protected Class<? extends ExecutionFlow> getBeanClass(Element element) {
 128                 String clss = element.getAttribute("class");
 129                 if (StringUtils.hasText(clss))
 130                         // TODO: check that it actually works
 131                         try {
 132                                 return (Class<? extends ExecutionFlow>) getClass()
 133                                                 .getClassLoader().loadClass(clss);
 134                         } catch (ClassNotFoundException e) {
 135                                 try {
 136                                         return (Class<? extends ExecutionFlow>) Thread
 137                                                         .currentThread().getContextClassLoader()
 138                                                         .loadClass(clss);
 139                                 } catch (ClassNotFoundException e1) {
 140                                         throw new SlcException("Cannot load class " + clss, e);
 141                                 }
 142                         }
 143                 else
 144                         return DefaultExecutionFlow.class;
 145         }
 146
 147         // parse nested bean definition
 148         // private Object parseBeanReference(Element element,
 149         // ParserContext parserContext, BeanDefinitionBuilder builder) {
 150         // return parserContext.getDelegate().parsePropertySubElement(element,
 151         // builder.getBeanDefinition());
 152         // }
 153
 154         @Override
 155         protected String resolveId(Element element,
 156                         AbstractBeanDefinition definition, ParserContext parserContext)
 157                         throws BeanDefinitionStoreException {
 158                 String name = element.getAttribute("name");
 159                 if (StringUtils.hasText(name)) {
 160                         return name;
 161                 } else {
 162                         return super.resolveId(element, definition, parserContext);
 163                 }
 164         }
 165
 166         protected boolean shouldGenerateIdAsFallback() {
 167                 return true;
 168         }
 169
 170 }