+package org.argeo.slc.core.execution.xml;
+
+import org.argeo.slc.SlcException;
+import org.springframework.beans.factory.config.BeanDefinition;
+import org.springframework.beans.factory.config.RuntimeBeanReference;
+import org.springframework.beans.factory.xml.ParserContext;
+import org.springframework.util.xml.DomUtils;
+import org.w3c.dom.Element;
+import org.w3c.dom.Node;
+import org.w3c.dom.NodeList;
+
+/**
+ * Utilities to simplify common tasks when interpreting a custom namespace and
+ * converting it into bean definitions.
+ */
+public class NamespaceUtils {
+ /**
+ * Returns the value defined either: directly by the the 'value' attribute,
+ * as reference by the 'ref' attribute or as a nested bean.
+ */
+ public static Object parseValue(Element element,
+ ParserContext parserContext,
+ BeanDefinition containingBeanDefintion, String valueTagName) {
+ Object value = null;
+ if (element.hasAttribute("value")) {
+ value = element.getAttribute("value");
+ }
+
+ if (element.hasAttribute("ref")) {
+ if (value != null)
+ throw new SlcException("Multiple value definition for "
+ + element);
+ value = new RuntimeBeanReference(element.getAttribute("ref"));
+ }
+
+ Element uniqueSubElem = null;
+ if (valueTagName != null) {
+ Element valueElem = DomUtils.getChildElementByTagName(element,
+ valueTagName);
+ if (valueElem != null) {
+ uniqueSubElem = findUniqueSubElement(valueElem);
+ if (uniqueSubElem == null)
+ throw new SlcException("No subelement found under "
+ + valueElem);
+ }
+ } else {// no intermediary tag
+ uniqueSubElem = findUniqueSubElement(element);
+ }
+
+ if (uniqueSubElem != null) {
+ if (value != null)
+ throw new SlcException("Multiple value definition for "
+ + element);
+ value = parseBeanReference(uniqueSubElem, parserContext,
+ containingBeanDefintion);
+ }
+ return value;
+ }
+
+ public static Element findUniqueSubElement(Element element) {
+ NodeList childNodes = element.getChildNodes();
+
+ Element uniqueSubElem = null;
+ for (int i = 0; i < childNodes.getLength(); i++) {
+ Node node = childNodes.item(i);
+ if (node != null && node instanceof Element) {
+ if (uniqueSubElem == null)
+ uniqueSubElem = (Element) node;
+ else
+ throw new SlcException(
+ "There are more than one sub element under "
+ + element);
+ }
+ }
+ return uniqueSubElem;
+ }
+
+ public static Object parseBeanReference(Element element,
+ ParserContext parserContext, BeanDefinition beanDefinition) {
+ return parserContext.getDelegate().parsePropertySubElement(element,
+ beanDefinition);
+ }
+
+}