Filter: add empty update handler and value method

source/Ox.UI/js/Form/Filter.js

@@ -35,7 +35,12 @@ Ox.Filter = function(options, self) {
                 sortKeys: [],
                 viewKeys: []
             })
-            .options(options || {});
+            .options(options || {})
+            .update({
+                query: function() {
+                    // ...
+                }
+            });
 
     // fixme: this should not happen, but some lists
     // have their query set to {} or their query operator set to ''
@@ -845,6 +850,10 @@ Ox.Filter = function(options, self) {
         }
     };
 
+    that.value = function() {
+        // ...
+    };
+
     return that;
 
 };