Added methods for retrieving SecurityLayer prefixes.

git-svn-id: https://joinup.ec.europa.eu/svn/moa-idspss/trunk@440 d688527b-c9ab-4aba-bd8d-4036d912da1d

1 files changed, 105 insertions, 0 deletions

diff --git a/common/src/at/gv/egovernment/moa/util/XPathUtils.java b/common/src/at/gv/egovernment/moa/util/XPathUtils.java
index 4ee160476..aa5a4fec5 100644
--- a/common/src/at/gv/egovernment/moa/util/XPathUtils.java
+++ b/common/src/at/gv/egovernment/moa/util/XPathUtils.java
@@ -412,5 +412,110 @@ public class XPathUtils {
     Attr attr = (Attr) XPathUtils.selectSingleNode(root, xpath);
     return attr != null ? attr.getValue() : def;
   }
+  
+  /**
+   * Return the SecurityLayer namespace prefix of the context element.
+   * If the context element has no prefix explicitely set (i.e. is specified
+   * within the <code>default</code> namespace), the method sets the prefix
+   * according to the value of the <code>xmlns</code> attribute of the context
+   * element.
+   * The returned prefix is needed for evaluating XPATH expressions.
+   * 
+   * @param contextElement The element to get a prefix from. 
+   *            
+   * @return  The string <code>sl10</code>, <code>sl11</code> or <code>sl</code>,
+   *          depending on the SecurityLayer namespace of the contextElement.
+   * 
+   * throws XpathException If the element has no prefix or no valid SecurityLayer
+   *                       namespace is used as default namespace.
+   */
+  public static String getSlPrefix (Element contextElement) throws XPathException {
+    String slPrefix = contextElement.getPrefix();
+    if (slPrefix != null) {
+      return slPrefix;
+    } else {
+      String nameSpace = contextElement.getAttribute("xmlns");
+      
+      if (nameSpace.equals(Constants.SL10_NS_URI)) {
+        slPrefix = Constants.SL10_PREFIX;
+      } else if (nameSpace.equals(Constants.SL12_NS_URI)) {
+        slPrefix = Constants.SL12_PREFIX;
+      } else if (nameSpace.equals(Constants.SL11_NS_URI)) {
+        slPrefix = Constants.SL11_PREFIX;
+      } else {
+        MessageProvider msg = MessageProvider.getInstance();
+        String message = msg.getMessage("xpath.00", new Object[] { "Ungültiger SecurityLayer Namespace: \"" + nameSpace + "\"."});
+        throw new XPathException(message, null);
+        
+      }
+      
+      return slPrefix;
+    }    
+  }
+  
+  
+  /**
+   * Return the SecurityLayer namespace prefix of the context element.
+   * If the context element is not the element that lies within the 
+   * SecurityLayer namespace. The Securitylayer namespace is derived from
+   * the <code>xmlns:sl10</code>, <code>sl11</code> or <code>sl</code> 
+   * attribute of the context element.
+   * 
+   * The returned prefix is needed for evaluating XPATH expressions.
+   * 
+   * @param contextElement The element to get a prefix for the Securitylayer namespace,
+   *                       that is used within the corresponding document. 
+   *            
+   * @return  The string <code>sl10</code>, <code>sl11</code> or <code>sl</code>,
+   *          depending on the SecurityLayer namespace of the contextElement.
+   * 
+   * throws XPathException If no (vlalid) SecurityLayer namespace prefix or namespace
+   *                       is defined.
+   */
+  public static String getSlPrefixFromNoRoot (Element contextElement) throws XPathException {
+    
+    String slPrefix = checkSLnsDeclaration(contextElement, Constants.SL10_PREFIX, Constants.SL10_NS_URI);
+    if (slPrefix == null) {
+      slPrefix = checkSLnsDeclaration(contextElement, Constants.SL11_PREFIX, Constants.SL11_NS_URI);
+    }
+    if (slPrefix == null) {
+      slPrefix = checkSLnsDeclaration(contextElement, Constants.SL12_PREFIX, Constants.SL12_NS_URI);
+    }       
+     
+    return slPrefix;
+       
+  }
+  
+  /**
+   * Checks if the context element has an attribute <code>xmlns:slPrefix</code> and
+   * if the prefix of that attribute corresponds with a valid SecurityLayer namespace.
+   * 
+   * @param contextElement  The element to be checked.
+   * @param slPrefix        The prefix which should be checked. Must be a valid SecurityLayer
+   *                        namespace prefix.
+   * @param slNameSpace     The SecurityLayer namespace that corresponds to the specified prefix.
+   *  
+   * @return                The valid SecurityLayer prefix or <code>null</code> if this prefix is
+   *                        not used.
+   * @throws XPathException
+   */
+  private static String checkSLnsDeclaration(Element contextElement, String slPrefix, String slNameSpace)
+      throws XPathException 
+  {
+    String nsAtt = "xmlns:" + slPrefix;
+    String nameSpace = contextElement.getAttribute(nsAtt);
+    if (nameSpace == "") {
+      return null;
+    } else {
+      // check if namespace is correct
+      if (nameSpace.equals(slNameSpace)) {
+        return slPrefix;
+      } else {
+        MessageProvider msg = MessageProvider.getInstance();
+        String message = msg.getMessage("xpath.00", new Object[] { "Ungültiger SecurityLayer Namespace: \"" + nameSpace + "\"."});
+        throw new XPathException(message, null);
+      }
+    }
+  }
 
 }