Start to implement the @attachTo XPath functions

git-svn-id: http://svn.us.apache.org/repos/asf/tuscany@747275 13f79535-47bb-0310-9956-ffa450edef68

2 files changed, 130 insertions, 0 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
new file mode 100644
index 0000000000..ffabad5644
--- /dev/null
+++ b/java/sca/modules/policy-xml/src/main/java/org/apache/tuscany/sca/policy/xml/PolicyXPathFunction.java
@@ -0,0 +1,61 @@
+/*
+ * 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 javax.xml.namespace.NamespaceContext;
+import javax.xml.namespace.QName;
+import javax.xml.xpath.XPathFunction;
+import javax.xml.xpath.XPathFunctionException;
+
+/**
+ * The SCA-defined XPath function
+ */
+public class PolicyXPathFunction implements XPathFunction {
+    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;
+    }
+
+    public Object evaluate(List args) throws XPathFunctionException {
+        // FIXME: [rfeng] To be implemented
+        String arg = (String)args.get(0);
+        System.out.println(functionName + "(" + arg + ")");
+        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
new file mode 100644
index 0000000000..733b208de7
--- /dev/null
+++ b/java/sca/modules/policy-xml/src/main/java/org/apache/tuscany/sca/policy/xml/PolicyXPathFunctionResolver.java
@@ -0,0 +1,69 @@
+/*
+ * 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 javax.xml.namespace.NamespaceContext;
+import javax.xml.namespace.QName;
+import javax.xml.xpath.XPathFunction;
+import javax.xml.xpath.XPathFunctionResolver;
+
+/**
+ * A resolver that handles SCA-defined XPath functions
+ * 
+ * Interface Related Functions
+ * <ul>
+ * <li>InterfaceRef( InterfaceName )
+ * <li>OperationRef( InterfaceName/OperationName )
+ * <li>MessageRef( InterfaceName/OperationName/MessageName )
+ * </ul>
+ * 
+ * Intent Related Functions
+ * <ul>
+ * <li>IntentRefs( IntentList )
+ * </ul>
+ * 
+ * URI Based Function
+ * <ul>
+ * <li>URIRef( URI )
+ * </ul>
+ */
+public class PolicyXPathFunctionResolver implements XPathFunctionResolver {
+    private NamespaceContext namespaceContext;
+
+    public PolicyXPathFunctionResolver(NamespaceContext namespaceContext) {
+        super();
+        this.namespaceContext = namespaceContext;
+    }
+
+    public XPathFunction resolveFunction(QName functionName, int arity) {
+        if (functionName == null) {
+            throw new NullPointerException("Function name is null");
+        }
+        if (PolicyXPathFunction.functions.contains(functionName)) {
+            if (arity == 1) {
+                return new PolicyXPathFunction(namespaceContext, functionName);
+            } else {
+                return null;
+            }
+        }
+        return null;
+    }
+
+}