Rebuild the composite by applying the @attachTo policy sets

git-svn-id: http://svn.us.apache.org/repos/asf/tuscany@815534 13f79535-47bb-0310-9956-ffa450edef68

2 files changed, 107 insertions, 18 deletions

diff --git a/java/sca/modules/policy-builder/src/main/java/org/apache/tuscany/sca/policy/builder/impl/PolicyAttachmentBuilderImpl.java b/java/sca/modules/policy-builder/src/main/java/org/apache/tuscany/sca/policy/builder/impl/PolicyAttachmentBuilderImpl.java
index e2550c1e88..e579d4b897 100644
--- a/java/sca/modules/policy-builder/src/main/java/org/apache/tuscany/sca/policy/builder/impl/PolicyAttachmentBuilderImpl.java
+++ b/java/sca/modules/policy-builder/src/main/java/org/apache/tuscany/sca/policy/builder/impl/PolicyAttachmentBuilderImpl.java
@@ -19,9 +19,16 @@
 
 package org.apache.tuscany.sca.policy.builder.impl;
 
+import static javax.xml.XMLConstants.DEFAULT_NS_PREFIX;
+import static javax.xml.XMLConstants.XMLNS_ATTRIBUTE;
+import static javax.xml.XMLConstants.XMLNS_ATTRIBUTE_NS_URI;
+
 import java.io.StringWriter;
+import java.util.StringTokenizer;
 
+import javax.xml.namespace.QName;
 import javax.xml.stream.XMLOutputFactory;
+import javax.xml.stream.XMLStreamReader;
 import javax.xml.stream.XMLStreamWriter;
 import javax.xml.xpath.XPathConstants;
 import javax.xml.xpath.XPathExpression;
@@ -39,8 +46,9 @@ import org.apache.tuscany.sca.core.FactoryExtensionPoint;
 import org.apache.tuscany.sca.definitions.Definitions;
 import org.apache.tuscany.sca.monitor.Monitor;
 import org.apache.tuscany.sca.policy.PolicySet;
-import org.apache.tuscany.sca.policy.PolicySubject;
+import org.w3c.dom.Attr;
 import org.w3c.dom.Document;
+import org.w3c.dom.Element;
 import org.w3c.dom.Node;
 import org.w3c.dom.NodeList;
 
@@ -74,13 +82,22 @@ public class PolicyAttachmentBuilderImpl implements CompositeBuilder {
 
     public void build(Composite composite, Definitions definitions, Monitor monitor) throws CompositeBuilderException {
         try {
-            applyXPath(composite, definitions, monitor);
+            Composite patched = applyXPath(composite, definitions, monitor);
+            System.out.println(patched);
         } catch (Exception e) {
             throw new CompositeBuilderException(e);
         }
     }
 
-    private void applyXPath(Composite composite, Definitions definitions, Monitor monitor) throws Exception {
+    /**
+     * Apply the attachTo XPath against the composite model
+     * @param composite The orginal composite
+     * @param definitions SCA definitions that contain the policy sets
+     * @param monitor The monitor
+     * @return A reloaded composite
+     * @throws Exception
+     */
+    private Composite applyXPath(Composite composite, Definitions definitions, Monitor monitor) throws Exception {
         // First write the composite into a DOM document so that we can apply the xpath
         StringWriter sw = new StringWriter();
         XMLStreamWriter writer = staxHelper.createXMLStreamWriter(sw);
@@ -90,6 +107,7 @@ public class PolicyAttachmentBuilderImpl implements CompositeBuilder {
 
         Document document = domHelper.load(sw.toString());
 
+        boolean changed = false;
         for (PolicySet ps : definitions.getPolicySets()) {
             XPathExpression exp = ps.getAttachToXPathExpression();
             if (exp != null) {
@@ -97,21 +115,98 @@ public class PolicyAttachmentBuilderImpl implements CompositeBuilder {
                 for (int i = 0; i < nodes.getLength(); i++) {
                     Node node = nodes.item(i);
                     // The node can be a component, service, reference or binding
-                    node.getNamespaceURI();
-                    // Use the node to find the corresponding element in the java model
+                    if (attach(node, ps) && !changed) {
+                        changed = true;
+                    }
                 }
             }
         }
+
+        if (changed) {
+            XMLStreamReader reader = staxHelper.createXMLStreamReader(document);
+            reader.nextTag();
+            Composite patchedComposite = (Composite)processor.read(reader);
+            return patchedComposite;
+        } else {
+            return composite;
+        }
     }
 
     /**
-     * Look up the corresponding Java model within the composite based on the DOM node
-     * @param composite
-     * @param node
-     * @return
+     * Attach the policySet to the given DOM node 
+     * @param node The DOM node (should be an element)
+     * @param policySet The policy set to be attached
+     * @return true if the element is changed, false if the element already contains the same policy set
+     * and no change is made
      */
-    private PolicySubject lookup(Composite composite, Node node) {
-        return null;
+    private boolean attach(Node node, PolicySet policySet) {
+        Element element = (Element)node;
+        Document document = element.getOwnerDocument();
+
+        QName qname = policySet.getName();
+        String prefix = DOMHelper.getPrefix(element, qname.getNamespaceURI());
+        if (prefix == null) {
+            // Find the a non-conflicting prefix
+            int i = 0;
+            while (true) {
+                prefix = "ns" + i;
+                String ns = DOMHelper.getNamespaceURI(element, prefix);
+                if (ns == null) {
+                    break;
+                }
+            }
+            // Declare the namespace
+            Attr nsAttr = document.createAttributeNS(XMLNS_ATTRIBUTE_NS_URI, XMLNS_ATTRIBUTE + ":" + prefix);
+            nsAttr.setValue(qname.getNamespaceURI());
+            element.setAttributeNodeNS(nsAttr);
+        }
+        // Form the value as a qualified name
+        String qvalue = null;
+        if (DEFAULT_NS_PREFIX.equals(prefix)) {
+            qvalue = qname.getLocalPart();
+        } else {
+            qvalue = prefix + ":" + qname.getLocalPart();
+        }
+
+        // Check if the attribute exists
+        Attr attr = element.getAttributeNode("policySets");
+        if (attr == null) {
+            // Create the policySets attr
+            attr = document.createAttributeNS(null, "policySets");
+            attr.setValue(qvalue);
+            element.setAttributeNodeNS(attr);
+            return true;
+        } else {
+            // Append to the existing value
+            boolean duplicate = false;
+            String value = attr.getValue();
+            StringTokenizer tokenizer = new StringTokenizer(value);
+            while (tokenizer.hasMoreTokens()) {
+                String ps = tokenizer.nextToken();
+                int index = ps.indexOf(':');
+                String ns = null;
+                String localName = null;
+                if (index == -1) {
+                    ns = DOMHelper.getNamespaceURI(element, DEFAULT_NS_PREFIX);
+                    localName = ps;
+                } else {
+                    ns = DOMHelper.getNamespaceURI(element, ps.substring(0, index));
+                    localName = ps.substring(index + 1);
+                }
+                QName psName = new QName(ns, localName);
+                if (qname.equals(psName)) {
+                    duplicate = true;
+                    break;
+                }
+            }
+            if (!duplicate) {
+                // REVIEW: [rfeng] How to comply to POL40012?
+                value = value + " " + qvalue;
+                attr.setValue(value.trim());
+                return true;
+            }
+            return false;
+        }
     }
 
 }
diff --git a/java/sca/modules/policy-builder/src/test/java/org/apache/tuscany/sca/policy/builder/impl/PolicyAttachmentTestCase.java b/java/sca/modules/policy-builder/src/test/java/org/apache/tuscany/sca/policy/builder/impl/PolicyAttachmentTestCase.java
index d2c3f4eeec..d8c39ae65e 100644
--- a/java/sca/modules/policy-builder/src/test/java/org/apache/tuscany/sca/policy/builder/impl/PolicyAttachmentTestCase.java
+++ b/java/sca/modules/policy-builder/src/test/java/org/apache/tuscany/sca/policy/builder/impl/PolicyAttachmentTestCase.java
@@ -19,18 +19,13 @@
 
 package org.apache.tuscany.sca.policy.builder.impl;
 
-import java.io.IOException;
 import java.io.InputStream;
 import java.net.URL;
 
-import javax.xml.stream.FactoryConfigurationError;
 import javax.xml.stream.XMLInputFactory;
-import javax.xml.stream.XMLStreamException;
 import javax.xml.stream.XMLStreamReader;
 
 import org.apache.tuscany.sca.assembly.Composite;
-import org.apache.tuscany.sca.assembly.builder.CompositeBuilderException;
-import org.apache.tuscany.sca.contribution.processor.ContributionReadException;
 import org.apache.tuscany.sca.contribution.processor.ExtensibleStAXArtifactProcessor;
 import org.apache.tuscany.sca.contribution.processor.StAXArtifactProcessor;
 import org.apache.tuscany.sca.contribution.processor.StAXArtifactProcessorExtensionPoint;
@@ -53,8 +48,7 @@ public class PolicyAttachmentTestCase {
     private Monitor monitor;
 
     @Test
-    public void testBuild() throws FactoryConfigurationError, IOException, XMLStreamException,
-        ContributionReadException, CompositeBuilderException {
+    public void testBuild() throws Exception {
         DefaultExtensionPointRegistry extensionPoints = new DefaultExtensionPointRegistry();
         XMLInputFactory inputFactory = XMLInputFactory.newInstance();
         // Create a monitor