Checkpoint of code/config for the action config definition and externalisation task

git-svn-id: https://svn.alfresco.com/repos/alfresco-enterprise/alfresco/HEAD/root@2543 c4b6b30b-aa2e-2d43-bbcb-ca4b014f7261

source/java/org/alfresco/web/action/ActionEvaluator.java

@@ -0,0 +1,34 @@
+/*
+ * Copyright (C) 2005 Alfresco, Inc.
+ *
+ * Licensed under the Mozilla Public License version 1.1 
+ * with a permitted attribution clause. You may obtain a
+ * copy of the License at
+ *
+ *   http://www.alfresco.org/legal/license.txt
+ *
+ * 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.alfresco.web.action;
+
+import org.alfresco.web.bean.repository.Node;
+
+/**
+ * Contract supported by all classes that provide dynamic evaluation for a UI action.
+ * <p>
+ * Evaluators are supplied with a Node instance context object.
+ * <p>
+ * The evaluator should decide if the action precondition is valid based on the appropriate
+ * logic and the properties etc. of the Node context and return the result.
+ * 
+ * @author Kevin Roast
+ */
+public interface ActionEvaluator
+{
+   public boolean evaluate(Node node);
+}