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