angularjs - TypeError: Cannot read property '$fetch' of undefined -

i using angular-js,angular-restmod , ui-router build app has following restmod models

    app.factory('event', function(restmod) {        return restmod.model('v1/events').mix(          {            user: {belongsto: 'user', key: 'user_id'}          }        );     });      app.factory('user', function(restmod) {       return restmod.model('v1/users');     }); 

i have controller lists events present in database

    app.controller('eventscontroller', function($scope,event,user) {         $scope.eventslist = [];         var events = event.$search();        (event in events) {         event.user.$fetch();        }        $scope.eventslist = events;     }) 

i getting error - typeerror: cannot read property '$fetch' of undefined line 'e.user.$fetch();'

i cannot figure out wrong in code. can please.