Prototype a way to access the context node for sca XPath funcitons

git-svn-id: http://svn.us.apache.org/repos/asf/tuscany@750627 13f79535-47bb-0310-9956-ffa450edef68

3 files changed, 38 insertions, 14 deletions

diff --git a/java/sca/modules/policy-xml/src/main/java/org/apache/tuscany/sca/policy/xml/PolicyXPathFunction.java b/java/sca/modules/policy-xml/src/main/java/org/apache/tuscany/sca/policy/xml/PolicyXPathFunction.java
index f015fc90fb..1b6d64e4f7 100644
--- a/java/sca/modules/policy-xml/src/main/java/org/apache/tuscany/sca/policy/xml/PolicyXPathFunction.java
+++ b/java/sca/modules/policy-xml/src/main/java/org/apache/tuscany/sca/policy/xml/PolicyXPathFunction.java
@@ -23,16 +23,23 @@ import java.util.Arrays;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
+import java.util.logging.Level;
+import java.util.logging.Logger;
 
 import javax.xml.namespace.NamespaceContext;
 import javax.xml.namespace.QName;
 import javax.xml.xpath.XPathFunction;
 import javax.xml.xpath.XPathFunctionException;
 
+import org.w3c.dom.Node;
+import org.w3c.dom.NodeList;
+
 /**
  * The SCA-defined XPath function
  */
 public class PolicyXPathFunction implements XPathFunction {
+    private static Logger logger = Logger.getLogger(PolicyXPathFunction.class.getName());
+    
     static final QName InterfaceRef = new QName(PolicyConstants.SCA11_NS, "InterfaceRef");
     static final QName OperationRef = new QName(PolicyConstants.SCA11_NS, "OperationRef");
     static final QName MessageRef = new QName(PolicyConstants.SCA11_NS, "MessageRef");
@@ -51,12 +58,25 @@ public class PolicyXPathFunction implements XPathFunction {
         this.functionName = functionName;
     }
 
+    private Node getContextNode(List args) {
+        if (args.size() >= 2) {
+            NodeList nodeList = (NodeList)args.get(1);
+            if (nodeList.getLength() > 0) {
+                return nodeList.item(0);
+            }
+        }
+        return null;
+    }
+    
     public Object evaluate(List args) throws XPathFunctionException {
-        System.out.println(functionName + "(" + args + ")");
-        // FIXME: [rfeng] To be implemented
+        if (logger.isLoggable(Level.FINE)) {
+            logger.fine(functionName + "(" + args + ")");
+        }
+        
         String arg = (String)args.get(0);
+        Node node = getContextNode(args);
         if (InterfaceRef.equals(functionName)) {
-            return evaluateInterface(arg);
+            return evaluateInterface(arg, node);
         } else if (OperationRef.equals(functionName)) {
             String[] params = arg.split("/");
             if (params.length != 2) {
@@ -64,7 +84,7 @@ public class PolicyXPathFunction implements XPathFunction {
             }
             String interfaceName = params[0];
             String operationName = params[1];
-            return evaluateOperation(interfaceName, operationName);
+            return evaluateOperation(interfaceName, operationName, node);
         } else if (MessageRef.equals(functionName)) {
             String[] params = arg.split("/");
             if (params.length != 3) {
@@ -73,34 +93,34 @@ public class PolicyXPathFunction implements XPathFunction {
             String interfaceName = params[0];
             String operationName = params[1];
             String messageName = params[2];
-            return evaluateMessage(interfaceName, operationName, messageName);
+            return evaluateMessage(interfaceName, operationName, messageName, node);
         } else if (URIRef.equals(functionName)) {
-            return evaluateURI(arg);
+            return evaluateURI(arg, node);
         } else if (IntentRefs.equals(functionName)) {
             String[] intents = arg.split("(\\s)+");
-            return evaluateIntents(intents);
+            return evaluateIntents(intents, node);
         } else {
             return Boolean.FALSE;
         }
     }
 
-    private Boolean evaluateInterface(String interfaceName) {
+    private Boolean evaluateInterface(String interfaceName, Node node) {
         return Boolean.FALSE;
     }
 
-    private Boolean evaluateOperation(String interfaceName, String operationName) {
+    private Boolean evaluateOperation(String interfaceName, String operationName, Node node) {
         return Boolean.FALSE;
     }
 
-    private Boolean evaluateMessage(String interfaceName, String operationName, String messageName) {
+    private Boolean evaluateMessage(String interfaceName, String operationName, String messageName, Node node) {
         return Boolean.FALSE;
     }
 
-    private Boolean evaluateURI(String uri) {
+    private Boolean evaluateURI(String uri, Node node) {
         return Boolean.FALSE;
     }
 
-    private Boolean evaluateIntents(String[] intents) {
+    private Boolean evaluateIntents(String[] intents, Node node) {
         return Boolean.FALSE;
     }
 
diff --git a/java/sca/modules/policy-xml/src/main/java/org/apache/tuscany/sca/policy/xml/PolicyXPathFunctionResolver.java b/java/sca/modules/policy-xml/src/main/java/org/apache/tuscany/sca/policy/xml/PolicyXPathFunctionResolver.java
index 2d04a27cd7..ca44667903 100644
--- a/java/sca/modules/policy-xml/src/main/java/org/apache/tuscany/sca/policy/xml/PolicyXPathFunctionResolver.java
+++ b/java/sca/modules/policy-xml/src/main/java/org/apache/tuscany/sca/policy/xml/PolicyXPathFunctionResolver.java
@@ -57,7 +57,10 @@ public class PolicyXPathFunctionResolver implements XPathFunctionResolver {
             throw new NullPointerException("Function name is null");
         }
         if (PolicyXPathFunction.functions.contains(functionName)) {
-            if (arity == 1) {
+            if (arity >= 1) {
+                // We are relaxing the arity here so that we can pass in the context node
+                // by modifying the original xpath so that sca functions take self::node()
+                // as the 2nd argument
                 return new PolicyXPathFunction(namespaceContext, functionName);
             } else {
                 throw new IllegalArgumentException("Invalid number of arguments: " + arity);
diff --git a/java/sca/modules/policy-xml/src/test/java/org/apache/tuscany/sca/policy/xml/PolicyXPathFunctionResolverTestCase.java b/java/sca/modules/policy-xml/src/test/java/org/apache/tuscany/sca/policy/xml/PolicyXPathFunctionResolverTestCase.java
index 7b647819b4..c9976a93b4 100644
--- a/java/sca/modules/policy-xml/src/test/java/org/apache/tuscany/sca/policy/xml/PolicyXPathFunctionResolverTestCase.java
+++ b/java/sca/modules/policy-xml/src/test/java/org/apache/tuscany/sca/policy/xml/PolicyXPathFunctionResolverTestCase.java
@@ -55,7 +55,8 @@ public class PolicyXPathFunctionResolverTestCase {
     @Test
     public void testIntentsRef() throws Exception {
         InputSource xml = new InputSource(getClass().getResourceAsStream("Calculator.composite"));
-        XPathExpression exp = xpath.compile("//sca:composite/sca:component[sca:IntentRefs('sca:confidentiality')]");
+        // Test the rewrite of xpath so that the self:node() is passed into the SCA function
+        XPathExpression exp = xpath.compile("//sca:composite/sca:component[sca:IntentRefs('sca:confidentiality', self::node())]");
         Object result = exp.evaluate(xml, XPathConstants.NODESET);
         Assert.assertTrue(result instanceof NodeList);
         NodeList nodes = (NodeList)result;