app.js

    var _DC_ID = null;
             function _getRetMsg() {
               var ret = '';
               switch ($state.current.name) {
               case 'workspace.datacard.edit':
               case 'bg-data.module.datacard.edit':
                 _DC_ID = $stateParams.id;
                 ret = 'dc edit ws';
                 break;
               case 'workspace.datacard.transform':
               case 'bg-data.module.datacard.transform':
                 _DC_ID = $stateParams.dcId;
                 ret = 'dc edit transform';
                 break;
               }
               return ret;
             }

             window.addEventListener('beforeunload', function(e) {
               var confirmationMessage = _getRetMsg();

               if (confirmationMessage !== '') {
                 if (navigator.userAgent.toLowerCase().indexOf('firefox') > -1) {
                   $injector.get('DataCardService').releaseLockDc(null, _DC_ID);
                   setTimeout( function() {
                     $injector.get('DataCardService').lockDc(null, _DC_ID);
                   });
                 }
                 (e || window.event).returnValue = confirmationMessage; //Gecko + IE
                 return confirmationMessage; //Webkit, Safari, Chrome etc.
               }
             });

             window.addEventListener('unload', function(e) {
               $injector.get('DataCardService').releaseLockDc(null, _DC_ID);
             });