1 files changed, 158 insertions, 0 deletions
diff --git a/tags/java/sca/2.0-M4-RC1/modules/assembly-xml/src/main/java/org/apache/tuscany/sca/policy/xml/PolicyXPathFunction.java b/tags/java/sca/2.0-M4-RC1/modules/assembly-xml/src/main/java/org/apache/tuscany/sca/policy/xml/PolicyXPathFunction.java
new file mode 100644
index 0000000000..10f142c67b
--- /dev/null
+++ b/tags/java/sca/2.0-M4-RC1/modules/assembly-xml/src/main/java/org/apache/tuscany/sca/policy/xml/PolicyXPathFunction.java
@@ -0,0 +1,158 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ * 
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.    
+ */
+
+package org.apache.tuscany.sca.policy.xml;
+
+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 java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+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");
+    static final QName IntentRefs = new QName(PolicyConstants.SCA11_NS, "IntentRefs");
+    static final QName URIRef = new QName(PolicyConstants.SCA11_NS, "URIRef");
+
+    static final Set<QName> functions =
+        new HashSet<QName>(Arrays.asList(InterfaceRef, OperationRef, MessageRef, IntentRefs, URIRef));
+
+    private NamespaceContext namespaceContext;
+    private final QName functionName;
+
+    public PolicyXPathFunction(NamespaceContext namespaceContext, QName functionName) {
+        super();
+        this.namespaceContext = namespaceContext;
+        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 {
+        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, node);
+        } else if (OperationRef.equals(functionName)) {
+            String[] params = arg.split("/");
+            if (params.length != 2) {
+                throw new IllegalArgumentException("Invalid argument: " + arg);
+            }
+            String interfaceName = params[0];
+            String operationName = params[1];
+            return evaluateOperation(interfaceName, operationName, node);
+        } else if (MessageRef.equals(functionName)) {
+            String[] params = arg.split("/");
+            if (params.length != 3) {
+                throw new IllegalArgumentException("Invalid argument: " + arg);
+            }
+            String interfaceName = params[0];
+            String operationName = params[1];
+            String messageName = params[2];
+            return evaluateMessage(interfaceName, operationName, messageName, node);
+        } else if (URIRef.equals(functionName)) {
+            return evaluateURI(arg, node);
+        } else if (IntentRefs.equals(functionName)) {
+            String[] intents = arg.split("(\\s)+");
+            return evaluateIntents(intents, node);
+        } else {
+            return Boolean.FALSE;
+        }
+    }
+
+    private Boolean evaluateInterface(String interfaceName, Node node) {
+        return Boolean.FALSE;
+    }
+
+    private Boolean evaluateOperation(String interfaceName, String operationName, Node node) {
+        return Boolean.FALSE;
+    }
+
+    private Boolean evaluateMessage(String interfaceName, String operationName, String messageName, Node node) {
+        return Boolean.FALSE;
+    }
+
+    private Boolean evaluateURI(String uri, Node node) {
+        return Boolean.FALSE;
+    }
+
+    private Boolean evaluateIntents(String[] intents, Node node) {
+        return Boolean.FALSE;
+    }
+
+    private static Pattern FUNCTION;
+    static {
+        String functionPattern = "(URIRef|InterfaceRef|OperationRef|MessageRef|IntentRefs)\\s*\\((.*)\\)";
+        FUNCTION = Pattern.compile(functionPattern);
+    }
+
+    public static String normalize(String attachTo) {
+        Matcher matcher = FUNCTION.matcher(attachTo);
+        boolean result = matcher.find();
+        if (result) {
+            StringBuffer sb = new StringBuffer();
+            do {
+                String function = matcher.group(1);
+                String args = matcher.group(2);
+                String replacement = null;
+                if (args.trim().length() > 0) {
+                    replacement = function + "(" + args + "," + "self::node())";
+                } else {
+                    replacement = function + "(self::node())";
+                }
+                matcher.appendReplacement(sb, replacement);
+                result = matcher.find();
+            } while (result);
+            matcher.appendTail(sb);
+            return sb.toString();
+        }
+        return attachTo;
+    }
+
+}