runtime/org.argeo.slc.core/src/main/java/org/argeo/slc/core/execution/xml/NamespaceUtils.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.slc.core.execution.xml;
  18
  19 import org.argeo.slc.SlcException;
  20 import org.springframework.beans.factory.config.BeanDefinition;
  21 import org.springframework.beans.factory.config.RuntimeBeanReference;
  22 import org.springframework.beans.factory.xml.BeanDefinitionParserDelegate;
  23 import org.springframework.beans.factory.xml.ParserContext;
  24 import org.springframework.util.xml.DomUtils;
  25 import org.w3c.dom.Element;
  26 import org.w3c.dom.Node;
  27 import org.w3c.dom.NodeList;
  28
  29 /**
  30  * Utilities to simplify common tasks when interpreting a custom namespace and
  31  * converting it into bean definitions.
  32  */
  33 public class NamespaceUtils {
  34         // private final static Log log = LogFactory.getLog(NamespaceUtils.class);
  35
  36         /**
  37          * Returns the value defined either: directly by the the 'value' attribute,
  38          * as reference by the 'ref' attribute or as a nested bean.
  39          */
  40         public static Object parseValue(Element element,
  41                         ParserContext parserContext,
  42                         BeanDefinition containingBeanDefintion, String valueTagName) {
  43                 Object value = null;
  44                 if (element.hasAttribute("value")) {
  45                         value = element.getAttribute("value");
  46                 }
  47
  48                 if (element.hasAttribute("ref")) {
  49                         if (value != null)
  50                                 throw new SlcException("Multiple value definition for "
  51                                                 + element);
  52                         value = new RuntimeBeanReference(element.getAttribute("ref"));
  53                 }
  54
  55                 Element uniqueSubElem = null;
  56                 if (valueTagName != null) {
  57                         Element valueElem = DomUtils.getChildElementByTagName(element,
  58                                         valueTagName);
  59                         if (valueElem != null) {
  60                                 uniqueSubElem = findUniqueSubElement(valueElem);
  61                                 if (uniqueSubElem == null)
  62                                         throw new SlcException("No subelement found under "
  63                                                         + valueElem);
  64                         }
  65                 } else {// no intermediary tag
  66                         uniqueSubElem = findUniqueSubElement(element);
  67                 }
  68
  69                 if (uniqueSubElem != null) {
  70                         if (value != null)
  71                                 throw new SlcException("Multiple value definition for "
  72                                                 + element);
  73                         value = parseBeanOrReference(uniqueSubElem, parserContext,
  74                                         containingBeanDefintion);
  75                 }
  76                 return value;
  77         }
  78
  79         public static Element findUniqueSubElement(Element element) {
  80                 NodeList childNodes = element.getChildNodes();
  81
  82                 Element uniqueSubElem = null;
  83                 for (int i = 0; i < childNodes.getLength(); i++) {
  84                         Node node = childNodes.item(i);
  85                         if (node != null && node instanceof Element) {
  86                                 if (uniqueSubElem == null)
  87                                         uniqueSubElem = (Element) node;
  88                                 else
  89                                         throw new SlcException(
  90                                                         "There are more than one sub element under "
  91                                                                         + element);
  92                         }
  93                 }
  94                 return uniqueSubElem;
  95         }
  96
  97         public static Object parseBeanOrReference(Element element,
  98                         ParserContext parserContext, BeanDefinition beanDefinition) {
  99                 // return parserContext.getDelegate().parsePropertySubElement(element,
 100                 // beanDefinition);
 101
 102                 BeanDefinitionParserDelegate deleg = parserContext.getDelegate();
 103                 // if ("bean".equals(element.getNodeName()))
 104                 // return deleg.parseBeanDefinitionElement(element, beanDefinition);
 105                 // else
 106                 return deleg.parsePropertySubElement(element, beanDefinition);
 107         }
 108 }