How to get the Previous State with Params using ui-router

Question

Problem Statement :

I have a button "add comment" , I should be able to add comment only when i have logged into the system.

But problem is I cannot come back to "add comment" page after login, because I dont know the previous state or cannot get the previous state.

Is there any cleaner solution to this ? Should i have login page a modal rather than a new page ?

I have seen all the questions that is taking about previous state and also the possible answers ( yes, i am taking about $rootscope and $stateChangeSuccess). But it does not clearly put forward the solutions.

Other possible solution is as below http://christopherthielen.github.io/ui-router-extras/example/previous/index.html#

I also saw https://github.com/angular-ui/ui-router/issues/92. but again, i was not sure what is the correct answer.

Could someone clearly state a good solution. Is using rootscope a good one ?

Answer 1

Should i have login page a modal rather than a new page? That is a design decision. You can have whatever fits your app and is to your liking.

Is using rootscope a good one? I feel its quite a good solution. Here's how I would do it:

Save previous state manually:

Create a state change listener:

    $rootScope.$on('$stateChangeSuccess', function(event, to, toParams, from, fromParams) {
        //save the previous state in a rootScope variable so that it's accessible from everywhere
        $rootScope.previousState = from;
    });
  }]);

Instead of using ui-sref, put a click function for the comment button.

$scope.commentHandler = function(){
    //check if user is logged in, let the user post the comment

    //else take him to login page
}

Then you can use $state.go($rootScope.previousState.name) after user has logged in to go back to comment page.

-OR -

You could provide a small login box in place of the "Post comment" button if user is not logged in.

Answer 2

For ui-router v1.0.0+, state change events have been deprecated.

An updated version of Arjun's state change listener would be

$transitions.onStart({}, function (transition) {
    $rootScope.previousState = transition.from();
});