--- a/src/main/java/de/mpiwg/itgroup/annotations/Annotation.java	Fri Jul 13 17:22:05 2012 +0200
+++ b/src/main/java/de/mpiwg/itgroup/annotations/Annotation.java	Fri Jul 13 20:41:02 2012 +0200
@@ -80,6 +80,53 @@
      */
     protected Actor readPermission;
     
+    
+    /**
+     * Returns if the requested action is allowed on this annotation.
+     * 
+     * @param action
+     * @param userId
+     * @return
+     */
+    public boolean isActionAllowed(String action, String userId) {
+        if (action.equals("read")) {
+            Actor reader = getReadPermission();
+            if (reader == null) {
+                return true;
+            } else {
+                return reader.isEquivalentWith(userId);
+            }
+        } else if (action.equals("update")) {
+            // require at least an authenticated user
+            if (userId == null) return false;
+            Actor updater = getUpdatePermission();
+            if (updater == null) {
+                return true;
+            } else {
+                return updater.isEquivalentWith(userId);
+            }
+        } else if (action.equals("delete")) {
+            // require at least an authenticated user
+            if (userId == null) return false;
+            Actor updater = getUpdatePermission();
+            if (updater == null) {
+                return true;
+            } else {
+                return updater.isEquivalentWith(userId);
+            }
+        } else if (action.equals("admin")) {
+            // require at least an authenticated user
+            if (userId == null) return false;
+            Actor admin = getAdminPermission();
+            if (admin == null) {
+                return true;
+            } else {
+                return admin.isEquivalentWith(userId);
+            }
+        }
+        return false;
+    }
+    
     /**
      * @return the uri
      */