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

   1 package org.argeo.slc.core.execution.xml;
   2
   3 import org.argeo.slc.SlcException;
   4 import org.springframework.beans.factory.config.BeanDefinition;
   5 import org.springframework.beans.factory.config.RuntimeBeanReference;
   6 import org.springframework.beans.factory.xml.BeanDefinitionParserDelegate;
   7 import org.springframework.beans.factory.xml.ParserContext;
   8 import org.springframework.util.xml.DomUtils;
   9 import org.w3c.dom.Element;
  10 import org.w3c.dom.Node;
  11 import org.w3c.dom.NodeList;
  12
  13 /**
  14  * Utilities to simplify common tasks when interpreting a custom namespace and
  15  * converting it into bean definitions.
  16  */
  17 public class NamespaceUtils {
  18         // private final static Log log = LogFactory.getLog(NamespaceUtils.class);
  19
  20         /**
  21          * Returns the value defined either: directly by the the 'value' attribute,
  22          * as reference by the 'ref' attribute or as a nested bean.
  23          */
  24         public static Object parseValue(Element element,
  25                         ParserContext parserContext,
  26                         BeanDefinition containingBeanDefintion, String valueTagName) {
  27                 Object value = null;
  28                 if (element.hasAttribute("value")) {
  29                         value = element.getAttribute("value");
  30                 }
  31
  32                 if (element.hasAttribute("ref")) {
  33                         if (value != null)
  34                                 throw new SlcException("Multiple value definition for "
  35                                                 + element);
  36                         value = new RuntimeBeanReference(element.getAttribute("ref"));
  37                 }
  38
  39                 Element uniqueSubElem = null;
  40                 if (valueTagName != null) {
  41                         Element valueElem = DomUtils.getChildElementByTagName(element,
  42                                         valueTagName);
  43                         if (valueElem != null) {
  44                                 uniqueSubElem = findUniqueSubElement(valueElem);
  45                                 if (uniqueSubElem == null)
  46                                         throw new SlcException("No subelement found under "
  47                                                         + valueElem);
  48                         }
  49                 } else {// no intermediary tag
  50                         uniqueSubElem = findUniqueSubElement(element);
  51                 }
  52
  53                 if (uniqueSubElem != null) {
  54                         if (value != null)
  55                                 throw new SlcException("Multiple value definition for "
  56                                                 + element);
  57                         value = parseBeanOrReference(uniqueSubElem, parserContext,
  58                                         containingBeanDefintion);
  59                 }
  60                 return value;
  61         }
  62
  63         public static Element findUniqueSubElement(Element element) {
  64                 NodeList childNodes = element.getChildNodes();
  65
  66                 Element uniqueSubElem = null;
  67                 for (int i = 0; i < childNodes.getLength(); i++) {
  68                         Node node = childNodes.item(i);
  69                         if (node != null && node instanceof Element) {
  70                                 if (uniqueSubElem == null)
  71                                         uniqueSubElem = (Element) node;
  72                                 else
  73                                         throw new SlcException(
  74                                                         "There are more than one sub element under "
  75                                                                         + element);
  76                         }
  77                 }
  78                 return uniqueSubElem;
  79         }
  80
  81         public static Object parseBeanOrReference(Element element,
  82                         ParserContext parserContext, BeanDefinition beanDefinition) {
  83                 // return parserContext.getDelegate().parsePropertySubElement(element,
  84                 // beanDefinition);
  85
  86                 BeanDefinitionParserDelegate deleg = parserContext.getDelegate();
  87                 // if ("bean".equals(element.getNodeName()))
  88                 // return deleg.parseBeanDefinitionElement(element, beanDefinition);
  89                 // else
  90                 return deleg.parsePropertySubElement(element, beanDefinition);
  91         }
  92 }