diff --git a/addons/web/__openerp__.py b/addons/web/__openerp__.py
index 41a58cd3a07..96fb8b3af71 100644
--- a/addons/web/__openerp__.py
+++ b/addons/web/__openerp__.py
@@ -36,6 +36,7 @@
         "static/lib/underscore/underscore.string.js",
         "static/lib/labjs/LAB.src.js",
         "static/lib/py.parse/lib/py.js",
+        "static/lib/nivjs/src/niv.js",
         "static/src/js/boot.js",
         "static/src/js/core.js",
         "static/src/js/dates.js",
diff --git a/addons/web/static/lib/nivjs/src/niv.js b/addons/web/static/lib/nivjs/src/niv.js
index 773f1a49f47..893651d8008 100644
--- a/addons/web/static/lib/nivjs/src/niv.js
+++ b/addons/web/static/lib/nivjs/src/niv.js
@@ -24,105 +24,109 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 niv = (function() {
-	var niv = {};
+    var lib = {};
 
-	/*
+    /*
      * Simple JavaScript Inheritance By John Resig http://ejohn.org/ MIT
      * Licensed.
      */
-	// Inspired by base2 and Prototype
-	(function(){
-	  var initializing = false, fnTest = /xyz/.test(function(){xyz;}) ? /\b_super\b/ : /.*/;
-	  // The base Class implementation (does nothing)
-	  this.Class = function(){};
-	  
-	  // Create a new Class that inherits from this class
-	  this.Class.extend = function(prop) {
-	    var _super = this.prototype;
-	    
-	    // Instantiate a base class (but only create the instance,
-	    // don't run the init constructor)
-	    initializing = true;
-	    var prototype = new this();
-	    initializing = false;
-	    
-	    // Copy the properties over onto the new prototype
-	    for (var name in prop) {
-	      // Check if we're overwriting an existing function
-	      prototype[name] = typeof prop[name] == "function" && 
-	        typeof _super[name] == "function" && fnTest.test(prop[name]) ?
-	        (function(name, fn){
-	          return function() {
-	            var tmp = this._super;
-	            
-	            // Add a new ._super() method that is the same method
-	            // but on the super-class
-	            this._super = _super[name];
-	            
-	            // The method only need to be bound temporarily, so we
-	            // remove it when we're done executing
-	            var ret = fn.apply(this, arguments);        
-	            this._super = tmp;
-	            
-	            return ret;
-	          };
-	        })(name, prop[name]) :
-	        prop[name];
-	    }
-	    
-	    // The dummy class constructor
-	    function Class() {
-	      // All construction is actually done in the init method
-	      if ( !initializing && this.init )
-	        this.init.apply(this, arguments);
-	    }
-	    
-	    // Populate our constructed prototype object
-	    Class.prototype = prototype;
-	    
-	    // Enforce the constructor to be what we expect
-	    Class.prototype.constructor = Class;
+    // Inspired by base2 and Prototype
+    (function() {
+        var initializing = false, fnTest = /xyz/.test(function() {
+            xyz;
+        }) ? /\b_super\b/ : /.*/;
+        // The base Class implementation (does nothing)
+        this.Class = function() {
+        };
 
-	    // And make this class extendable
-	    Class.extend = arguments.callee;
-	    
-	    return Class;
-	  };
-	}).call(niv);
-	
-	niv.ParentedMixin = {
-	    __parented_mixin: true,
-	    setParent: function(parent) {
-	        if(this.getParent()) {
-	            if (this.getParent().__parented_mixin) {
-	                this.getParent().__parented_children = _.without(this.getParent().getChildren(), this);
-	            }
-	            this.__parented_parent = undefined;
-	        }
-	        this.__parented_parent = parent;
-	        if(parent && parent.__parented_mixin) {
-	            if (!parent.getChildren())
-	                parent.__parented_children = [];
-	            parent.getChildren().push(this);
-	        }
-	    },
-	    getParent: function() {
-	        return this.__parented_parent;
-	    },
-	    getChildren: function() {
-	        return this.__parented_children ? _.clone(this.__parented_children) : [];
-	    },
-	    isDestroyed: function() {
-	        return this.__parented_stopped;
-	    },
-	    destroy: function() {
-	        _.each(this.getChildren(), function(el) {
-	            el.destroy();
-	        });
-	        this.setParent(undefined);
-	        this.__parented_stopped = true;
-	    },
-	};
+        // Create a new Class that inherits from this class
+        this.Class.extend = function(prop) {
+            var _super = this.prototype;
 
-	return niv;
+            // Instantiate a base class (but only create the instance,
+            // don't run the init constructor)
+            initializing = true;
+            var prototype = new this();
+            initializing = false;
+
+            // Copy the properties over onto the new prototype
+            for ( var name in prop) {
+                // Check if we're overwriting an existing function
+                prototype[name] = typeof prop[name] == "function"
+                        && typeof _super[name] == "function"
+                        && fnTest.test(prop[name]) ? (function(name, fn) {
+                    return function() {
+                        var tmp = this._super;
+
+                        // Add a new ._super() method that is the same method
+                        // but on the super-class
+                        this._super = _super[name];
+
+                        // The method only need to be bound temporarily, so we
+                        // remove it when we're done executing
+                        var ret = fn.apply(this, arguments);
+                        this._super = tmp;
+
+                        return ret;
+                    };
+                })(name, prop[name]) : prop[name];
+            }
+
+            // The dummy class constructor
+            function Class() {
+                // All construction is actually done in the init method
+                if (!initializing && this.init)
+                    this.init.apply(this, arguments);
+            }
+
+            // Populate our constructed prototype object
+            Class.prototype = prototype;
+
+            // Enforce the constructor to be what we expect
+            Class.prototype.constructor = Class;
+
+            // And make this class extendable
+            Class.extend = arguments.callee;
+
+            return Class;
+        };
+    }).call(lib);
+
+    lib.ParentedMixin = {
+        __parented_mixin : true,
+        setParent : function(parent) {
+            if (this.getParent()) {
+                if (this.getParent().__parented_mixin) {
+                    this.getParent().__parented_children = _.without(this
+                            .getParent().getChildren(), this);
+                }
+                this.__parented_parent = undefined;
+            }
+            this.__parented_parent = parent;
+            if (parent && parent.__parented_mixin) {
+                if (!parent.__parented_children)
+                    parent.__parented_children = [];
+                parent.__parented_children.push(this);
+            }
+        },
+        getParent : function() {
+            return this.__parented_parent;
+        },
+        getChildren : function() {
+            return this.__parented_children ? _.clone(this.__parented_children)
+                    : [];
+        },
+        isDestroyed : function() {
+            return this.__parented_destroyed;
+        },
+        destroy : function() {
+            _.each(this.getChildren(), function(el) {
+                el.destroy();
+            });
+            this.setParent(undefined);
+            this.__parented_destroyed = true;
+        }
+    };
+
+    return lib;
 })();
diff --git a/addons/web/static/src/js/core.js b/addons/web/static/src/js/core.js
index fd0abcb0eb4..69ec98e7350 100644
--- a/addons/web/static/src/js/core.js
+++ b/addons/web/static/src/js/core.js
@@ -925,40 +925,6 @@ openerp.web.Connection = openerp.web.CallbackEnabled.extend( /** @lends openerp.
     }
 });
 
-openerp.web.ParentedMixin = {
-    __parented_mixin: true,
-    setParent: function(parent) {
-        if(this.getParent()) {
-            if (this.getParent().__parented_mixin) {
-                this.getParent().__parented_children = _.without(this.getParent().getChildren(), this);
-            }
-            this.__parented_parent = undefined;
-        }
-        this.__parented_parent = parent;
-        if(parent && parent.__parented_mixin) {
-            if (!parent.__parented_children)
-                parent.__parented_children = [];
-            parent.__parented_children.push(this);
-        }
-    },
-    getParent: function() {
-        return this.__parented_parent;
-    },
-    getChildren: function() {
-        return this.__parented_children ? _.clone(this.__parented_children) : [];
-    },
-    isDestroyed: function() {
-        return this.__parented_destroyed;
-    },
-    destroy: function() {
-        _.each(this.getChildren(), function(el) {
-            el.destroy();
-        });
-        this.setParent(undefined);
-        this.__parented_destroyed = true;
-    },
-};
-
 /**
  * Base class for all visual components. Provides a lot of functionalities helpful
  * for the management of a part of the DOM.
@@ -1007,7 +973,7 @@ openerp.web.ParentedMixin = {
  *
  * That will kill the widget in a clean way and erase its content from the dom.
  */
-openerp.web.Widget = openerp.web.CallbackEnabled.extend(openerp.web.ParentedMixin).extend(/** @lends openerp.web.Widget# */{
+openerp.web.Widget = openerp.web.CallbackEnabled.extend(niv.ParentedMixin).extend(/** @lends openerp.web.Widget# */{
     /**
      * The name of the QWeb template that will be used for rendering. Must be
      * redefined in subclasses or the default render() method can not be used.