Is there a way to dispatch an event from one Angular ui-router view to another view?

Question

Is there a way to dispatch an event from one Angular ui-router view to another view?

In order to change the login button to display "logged in as xxx" after authentication, I have structured my page into three views: header, content, footer. The login button is located in the header view. Upon clicking login, it transitions to the "app.login" state, allowing the content view to update for user input of username and password.

Below is the routing code snippet:

app.config(['$stateProvider', '$urlRouterProvider',
    function($stateProvider, $urlRouterProvider) {
    $stateProvider
    .state('app', {
        url: '/',
        views: {
            'header': {
                templateUrl: 'static/templates/header.html',
                controller: 'AppController'
            },
            'content': {
                templateUrl: 'static/templates/home.html',
                controller: 'HomeController'
            },
            'footer': {
                templateUrl: 'static/templates/footer.html',
            }
        }
    })
    .state('app.login', {
        url: 'login',
        views: {
            'content@': {
                templateUrl : 'static/templates/login.html',
                controller  : 'LoginController'
           }
        }
    })

The HTML template includes the following code snippet:

<li><span ng-if='loggedIn' class="navbar-text">
    Signed in as {{currentUser.username}}</span>
</li>

The LoginController sets a $scope.loggedIn flag to true upon successful authentication, but the challenge lies in populating that flag to the header view. While utilizing $scope.loggedIn directly in the HTML template poses scope issues between controllers, leveraging $scope.$emit and $scope.$on within parent-child controllers might not be feasible due to the separation of views.

Although resorting to $rootScope is an option, best practices discourage polluting the $rootScope unnecessarily. Given the commonality of this use case, there must be a simple solution that I am overlooking.

javascript angularjs angular-ui-router

Answer 1

Answer №1

If you're looking to streamline your authentication process, consider using a factory:

app.factory( 'AuthService', function() {
  var currentUser;

  return {
    login: function() {
      // handle login logic here 
    },
    logout: function() {
      // handle logout logic here 
    },
    isLoggedIn: function() {
      // check if user is logged in logic here 
    },
    currentUser: function() { 
      return currentUser; 
    }
  };
});

You can then inject the AuthService into your controllers. The code snippet below demonstrates how changes in values from the service can be monitored and synced:

app.controller( 'AppController', function( $scope, AuthService ) {
  $scope.$watch( AuthService.isLoggedIn, function ( isLoggedIn ) {
    $scope.isLoggedIn = isLoggedIn;
    $scope.currentUser = AuthService.currentUser();
  });
});

Answer 2

If you're looking to streamline your authentication process, consider using a factory:

app.factory( 'AuthService', function() {
  var currentUser;

  return {
    login: function() {
      // handle login logic here 
    },
    logout: function() {
      // handle logout logic here 
    },
    isLoggedIn: function() {
      // check if user is logged in logic here 
    },
    currentUser: function() { 
      return currentUser; 
    }
  };
});

You can then inject the AuthService into your controllers. The code snippet below demonstrates how changes in values from the service can be monitored and synced:

app.controller( 'AppController', function( $scope, AuthService ) {
  $scope.$watch( AuthService.isLoggedIn, function ( isLoggedIn ) {
    $scope.isLoggedIn = isLoggedIn;
    $scope.currentUser = AuthService.currentUser();
  });
});

Answer 3

Answer №2

When faced with such scenarios, my preferred approach is to utilize a coordination service. These services are created using the new keyword and then cached, essentially creating a singleton instance. By implementing a simple subscribe/publish pattern, you can easily manage communication between different components. A basic structure for this setup would look something like this:

angular.module('some-module').service('myCoordinationService', function() {
    var callbacks = [];
    this.register = function(cb) {
      callbacks.push(cb);
    };

    this.send(message) {
      callbacks.forEach(function(cb) {
        cb(message);
      });
    };
}).controller('controller1', ['myCoordinationService', function(myCoordinationService) {
  myCoordinationService.register(function(message) {
     console.log('I was called with ' + message);
  });
}).controller('controller2', ['myCoordinationService', function(myCoordinationService) {
  myCoordinationService.send(123);
});

Answer 4

When faced with such scenarios, my preferred approach is to utilize a coordination service. These services are created using the new keyword and then cached, essentially creating a singleton instance. By implementing a simple subscribe/publish pattern, you can easily manage communication between different components. A basic structure for this setup would look something like this:

angular.module('some-module').service('myCoordinationService', function() {
    var callbacks = [];
    this.register = function(cb) {
      callbacks.push(cb);
    };

    this.send(message) {
      callbacks.forEach(function(cb) {
        cb(message);
      });
    };
}).controller('controller1', ['myCoordinationService', function(myCoordinationService) {
  myCoordinationService.register(function(message) {
     console.log('I was called with ' + message);
  });
}).controller('controller2', ['myCoordinationService', function(myCoordinationService) {
  myCoordinationService.send(123);
});

Answer 5

Answer №3

Are you utilizing any service to store logged user data? Services act as singletons, making them ideal for managing this type of information without cluttering up the $rootScope.

app.controller('LoginController', ['authService', '$scope', function (authService, $scope) {
  $scope.login = function(username, password) {
    // Perform some validation
    authService.login(username, password);
  }
}]);

app.controller('HeaderController', ['authService', '$scope', function (authService, $scope) {
    $scope.authService = authService;
}]);

In your header html file:

<span ng-if="authService.isAuthenticated()">
    {{ authService.getCurrentUser().userName }}
</span>

Answer 6

Are you utilizing any service to store logged user data? Services act as singletons, making them ideal for managing this type of information without cluttering up the $rootScope.

app.controller('LoginController', ['authService', '$scope', function (authService, $scope) {
  $scope.login = function(username, password) {
    // Perform some validation
    authService.login(username, password);
  }
}]);

app.controller('HeaderController', ['authService', '$scope', function (authService, $scope) {
    $scope.authService = authService;
}]);

In your header html file:

<span ng-if="authService.isAuthenticated()">
    {{ authService.getCurrentUser().userName }}
</span>

Is there a way to dispatch an event from one Angular ui-router view to another view?

Answer №1

Answer №2

Answer №3

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