FlowBeanDefinitionParser.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.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         /** Whether the user has already be warned on path attribute usage. */
  46         private Boolean warnedAboutPathAttribute = false;
  47
  48         @Override
  49         protected void doParse(Element element, ParserContext parserContext,
  50                         BeanDefinitionBuilder builder) {
  51                 String path = element.getAttribute("path");
  52                 if (StringUtils.hasText(path)) {
  53                         builder.addPropertyValue("path", path);
  54
  55                         // warns user only once
  56                         if (!warnedAboutPathAttribute)
  57                                 log.warn("The path=\"\" attribute is deprecated"
  58                                                 + " and will be removed in a later release."
  59                                                 + " Use <flow:flow name=\"/my/path/flowName\">.");
  60                         warnedAboutPathAttribute = true;
  61                 }
  62
  63                 String spec = element.getAttribute("spec");
  64                 if (StringUtils.hasText(spec))
  65                         builder.getBeanDefinition().getConstructorArgumentValues()
  66                                         .addGenericArgumentValue(new RuntimeBeanReference(spec));
  67
  68                 String abstrac = element.getAttribute("abstract");
  69                 if (StringUtils.hasText(abstrac))
  70                         builder.setAbstract(Boolean.parseBoolean(abstrac));
  71
  72                 String parent = element.getAttribute("parent");
  73                 if (StringUtils.hasText(parent))
  74                         builder.setParentName(parent);
  75
  76                 builder.getBeanDefinition().setDescription(
  77                                 DomUtils.getChildElementValueByTagName(element, "description"));
  78
  79                 List<Element> argsElems = new ArrayList<Element>();
  80                 List<Element> execElems = new ArrayList<Element>();
  81                 List<Element> specElems = new ArrayList<Element>();
  82                 NodeList nodeList = element.getChildNodes();
  83                 for (int i = 0; i < nodeList.getLength(); i++) {
  84                         Node node = nodeList.item(i);
  85                         if (node instanceof Element) {
  86                                 if (DomUtils.nodeNameEquals(node, "arg"))
  87                                         argsElems.add((Element) node);
  88                                 else if (DomUtils.nodeNameEquals(node, "spec"))
  89                                         specElems.add((Element) node);
  90                                 else if (!DomUtils.nodeNameEquals(node, "description"))
  91                                         execElems.add((Element) node);
  92                         }
  93                 }
  94
  95                 // Arguments
  96                 if (argsElems.size() != 0) {
  97                         ManagedMap<String, Object> args = new ManagedMap<String, Object>(
  98                                         argsElems.size());
  99                         for (Element argElem : argsElems) {
 100                                 Object value = NamespaceUtils.parseValue(argElem,
 101                                                 parserContext, builder.getBeanDefinition(), null);
 102                                 if (value != null)
 103                                         args.put(argElem.getAttribute("name"), value);
 104                                 else
 105                                         throw new SlcException("No value defined.");
 106                         }
 107                         builder.getBeanDefinition().getConstructorArgumentValues()
 108                                         .addGenericArgumentValue(args);
 109                 }
 110
 111                 // Execution specs
 112                 if (StringUtils.hasText(spec) && specElems.size() != 0)
 113                         throw new SlcException("A flow cannot have multiple specs");
 114                 if (specElems.size() == 1) {
 115                         Object specObj = NamespaceUtils.parseBeanOrReference(
 116                                         specElems.get(0), parserContext,
 117                                         builder.getBeanDefinition());
 118                         builder.getBeanDefinition().getConstructorArgumentValues()
 119                                         .addGenericArgumentValue(specObj);
 120                 } else if (specElems.size() > 1)
 121                         throw new SlcException("A flow cannot have multiple specs");
 122
 123                 // Executables
 124                 if (execElems.size() != 0) {
 125                         ManagedList<Object> executables = new ManagedList<Object>(
 126                                         execElems.size());
 127                         for (Element child : execElems) {
 128                                 // child validity check is performed in xsd
 129                                 executables.add(NamespaceUtils.parseBeanOrReference(child,
 130                                                 parserContext, builder.getBeanDefinition()));
 131                         }
 132                         if (executables.size() > 0)
 133                                 builder.addPropertyValue("executables", executables);
 134                 }
 135         }
 136
 137         @SuppressWarnings("unchecked")
 138         @Override
 139         protected Class<? extends ExecutionFlow> getBeanClass(Element element) {
 140                 String clss = element.getAttribute("class");
 141                 if (StringUtils.hasText(clss))
 142                         // TODO: check that it actually works
 143                         try {
 144                                 return (Class<? extends ExecutionFlow>) getClass()
 145                                                 .getClassLoader().loadClass(clss);
 146                         } catch (ClassNotFoundException e) {
 147                                 try {
 148                                         return (Class<? extends ExecutionFlow>) Thread
 149                                                         .currentThread().getContextClassLoader()
 150                                                         .loadClass(clss);
 151                                 } catch (ClassNotFoundException e1) {
 152                                         throw new SlcException("Cannot load class " + clss, e);
 153                                 }
 154                         }
 155                 else
 156                         return DefaultExecutionFlow.class;
 157         }
 158
 159         // parse nested bean definition
 160         // private Object parseBeanReference(Element element,
 161         // ParserContext parserContext, BeanDefinitionBuilder builder) {
 162         // return parserContext.getDelegate().parsePropertySubElement(element,
 163         // builder.getBeanDefinition());
 164         // }
 165
 166         @Override
 167         protected String resolveId(Element element,
 168                         AbstractBeanDefinition definition, ParserContext parserContext)
 169                         throws BeanDefinitionStoreException {
 170                 String name = element.getAttribute("name");
 171                 if (StringUtils.hasText(name)) {
 172                         return name;
 173                 } else {
 174                         return super.resolveId(element, definition, parserContext);
 175                 }
 176         }
 177
 178         protected boolean shouldGenerateIdAsFallback() {
 179                 return true;
 180         }
 181
 182 }