AngularJS ng-show Not Working?

Question

I am trying to change my UI (ON LOAD) based on whether or not a token is present. I would like to show and hide my login div and my form div based on whether or not the token is present. For whatever reason, I cannot get ng-show to work. To simplify the problem I have the following:

https://jsfiddle.net/m1q7h9fn/3/

HTML

<div ng-app="nh-launch">
    <div ng-show="loginView">
        <h1>Login</h1>
    </div>

    <div ng-show="formView">
        <h1>Form</h1>
    </div>
</div>

JS

angular.module('nh-launch',[]).run(function($scope) {

var token = "valid";

    if (token == "valid") {
        $scope.loginView = false;
        $scope.formView = true;
        $scope.$apply();
    }
    else {
        $scope.loginView = true;
        $scope.formView = false;
        $scope.$apply();
    }

});

Answer 1

Change run to controller as:

 angular.module('nh-launch', []).controller('launch-controller', function($scope) { /* This run when page load... */ $scope.loginView = false; $scope.formView = true; $scope.changeView = function() { /* This run when click button */ $scope.token = ($scope.token == "valid" ? "" : "valid"); $scope.loginView = $scope.token == "valid"; $scope.formView = $scope.token != "valid"; }; }); 

 <script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script> <div ng-app="nh-launch" ng-controller="launch-controller"> <button type="button" ng-click="changeView();">Change</button> <div ng-show="loginView"> <h1>Login</h1> </div> <div ng-show="formView"> <h1>Form</h1> </div> </div> 

Answer 2

In MVC frameworks like AngularJS, the model ($scope) ties to the view. The glue connecting the two is the controller. That's why $scope variables should be declared in the controller. I would reorganize your code as follows

angular.module('nh-launch',[])
   .controller('myCtrl', ['$scope', function($scope) {

        var token = "valid";

        if (token == "valid") {
            $scope.loginView = false;
            $scope.formView = true;
            $scope.$apply();
        }
        else {
            $scope.loginView = true;
            $scope.formView = false;
            $scope.$apply();
        }

    }]);

And then create a reference to the controller with the ng-controller attribute. Your HTML should look as follows

<div ng-app="nh-launch">
  <div ng-controller="myCtrl">
    <div ng-show="loginView">
        <h1>Login</h1>
    </div>

    <div ng-show="formView">
        <h1>Form</h1>
    </div>
  </div>
</div>

Answer 3

There must be a controller which should be bound with View. So the following code will help you to get:

  <div ng-app="nh-launch">
    <div ng-controller="LoginCtrl">
        <div ng-show="loginView">
            <h1>Login</h1>
        </div>

        <div ng-show="formView">
            <h1>Form</h1>
        </div>
    </div>
    </div>
<script>
    angular.module('nh-launch',[]).controller('LoginCtrl',function($scope) {

        var token = "valid";

        if (token == "valid") {
            $scope.loginView = false;
            $scope.formView = true;
            $scope.$apply();
        }
        else {
            $scope.loginView = true;
            $scope.formView = false;
            $scope.$apply();
        }

    });
</script>

Answer 4

you don't need a separate controller (although you should use a controller and scope in real-world program).

You can inject the $rootscope. $scope.$apply $rootscope. $scope.$apply is not required.

I have tweaked your code https://jsfiddle.net/m1q7h9fn/8/