How to redirect in a ui-router resolver?

I am trying to redirect inside a ui-router resolve and wanted to know if there is a way to reroute in a router resolver. Currently this does not work as one would think.

resolver(auth, $state){
   if(!auth.isLoggedIn()){
       $state.go('noLoggedInPath');
   }
}

How does one redirect in a resolver correctly ?

My temp hack is this but I am not comfortable with it.

resolver(auth, $state, $timeout){
   if(!auth.isLoggedIn()){
        $timeout(function () {

             $state.go('noLoggedInPath');
        }, 0);
   }
}

Solution 1:

Yauheni's answer does work, but to get around the weird timeout thing, you can reject the promise, and catch that in the $stateChangeError event, and do your redirect there. Like so...

state('admin', {
  resolve: {
    auth: function(UserService, $q, permissionService) {
      var deferred = $q.defer();
      return UserService.load().then(function(user){
        if (permissionService.can(user, {goTo: state})) {
          return deferred.resolve({});
        } else {
          return deferred.reject({redirectTo: 'some_other_state'});
        }
      });
    }
  }
});

And then ui-router always broadcasts "stateChangeError", so you can do something like this..

$rootScope.$on('$stateChangeError', function(evt, to, toParams, from, fromParams, error) {
  if (error.redirectTo) {
    $state.go(error.redirectTo);
  } else {
    $state.go('error', {status: error.status})
  }
})

Solution 2:

You can return a promise from your resolver function that will indicate whether to continue navigating to the state or not. If you decide to navigate somewhere else - reject the promise and specify the proper state:

resolver($q, $state, $timeout, auth) {
    var deferred = $q.defer();

    // $timeout is an example; it also can be an xhr request or any other async function
    $timeout(function() {
      if (!auth.isLoggedIn()) {
        // user is not logged, do not proceed
        // instead, go to a different page
        $state.go('noLoggedInPath');
        deferred.reject();
      } else {
        // everything is fine, proceed
        deferred.resolve();
      }
    });

    return deferred.promise;
}

Plunkr here.

UPD: updated code and added plunkr. Looks like it only works if you put it inside a timeout function.

Solution 3:

I use this

   function Check($state, $q) {
        var deferred = $q.defer();
        if (condition) {
            deferred.resolve();
        }
        else {
            deferred.reject();
        }
        return deferred.promise.catch(function () { $state.go('path'); });
    }

Solution 4:

This is what I actually do, and I can't find a better solution

resolver($q, $timeout, myService) {
    if(!areParameterValuesValid() || !isEverythingLogicallyOk()){
        var deferred = $q.defer();
        $timeout(function() {
            $state.go('somewhere');
            deferred.reject();
        });
        return deferred.promise;
    } else {
        return myService.loadSomething(passingSomeParams);
    }        
}

Solution 5:

I think a much cleaner answer is to return an already rejected promise like so:

resolver(auth, $state, $q){
   if(!auth.isLoggedIn()){
       $state.go('noLoggedInPath');
       
       // Return rejected promise
       return $q.reject();
   }
   return true;
}