Call the parent's overridden method. For example:
Ext.define('My.own.A', { constructor: function(test) { alert(test); } }); Ext.define('My.own.B', { extend: 'My.own.A', constructor: function(test) { alert(test); this.callParent([test + 1]); } }); Ext.define('My.own.C', { extend: 'My.own.B', constructor: function() { alert("Going to call parent's overriden constructor..."); this.callParent(arguments); } }); var a = new My.own.A(1); // alerts '1' var b = new My.own.B(1); // alerts '1', then alerts '2' var c = new My.own.C(2); // alerts "Going to call parent's overriden constructor..." // alerts '2', then alerts '3'