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