Nick Sloan Nick Sloan - 1 month ago 7
AngularJS Question

Using $state methods with $stateChangeStart toState and fromState in Angular ui-router

I'm writing a handler for

$stateChangeStart
:

var stateChangeStartHandler = function(e, toState, toParams, fromState, fromParams) {
if (toState.includes('internal') && !$cookies.MySession) {
e.preventDefault();
// Some login stuff.
}
};

$rootScope.$on('$stateChangeStart', stateChangeStartHandler);


toState
does not have the includes method. Should I be doing something different, or is there a way to do what I'm trying to do?

Also, when //some login stuff includes a
$state.go(...)
, I get an infinite loop. What might cause that?




Here's a more complete example demonstrating what we eventually got to work:

angular.module('test', ['ui.router', 'ngCookies'])
.config(['$stateProvider', '$cookiesProvider', function($stateProvider, $cookiesProvider) {

$stateProvider
.state('public', {
abstract: true
})
.state('public.login', {
url: '/login'
})
.state('tool', {
abstract: true
})
.state('tool.suggestions', {
url: '/suggestions'
});

}])
.run(['$state', '$cookies', '$rootScope', function($state, $cookies, $rootScope) {
$rootScope.$on('$stateChangeStart', function(e, toState, toParams, fromState, fromParams) {

if (toState.name.indexOf('tool') > -1 && !$cookies.Session) {
// If logged out and transitioning to a logged in page:
e.preventDefault();
$state.go('public.login');
} else if (toState.name.indexOf('public') > -1 && $cookies.Session) {
// If logged in and transitioning to a logged out page:
e.preventDefault();
$state.go('tool.suggestions');
};
});
});


I don't like using
indexOf
to search for a particular state in the
toState
. It feels naive. I'm not sure why
toState
and
fromState
couldn't be an instance of the
$state
service, or why the
$state
service couldn't accept a state configuration override in its methods.

The infinite looping was caused by a mistake on our part. I don't love this, so I'm still looking for better answers.

Answer

Suggestion 1

When you add an object to $stateProvider.state that object is then passed with the state. So you can add additional properties which you can read later on when needed.

Example route configuration

$stateProvider
.state('public', {
    abstract: true,
    module: 'public'
})
.state('public.login', {
    url: '/login',
    module: 'public'
})
.state('tool', {
    abstract: true,
    module: 'private'
})
.state('tool.suggestions', {
    url: '/suggestions',
    module: 'private'
});

The $stateChangeStart event gives you acces to the toState and fromState objects. These state objects will contain the configuration properties.

Example check for the custom module property

$rootScope.$on('$stateChangeStart', function(e, toState, toParams, fromState, fromParams) {
    if (toState.module === 'private' && !$cookies.Session) {
        // If logged out and transitioning to a logged in page:
        e.preventDefault();
        $state.go('public.login');
    } else if (toState.module === 'public' && $cookies.Session) {
        // If logged in and transitioning to a logged out page:
        e.preventDefault();
        $state.go('tool.suggestions');
    };
});

I didn't change the logic of the cookies because I think that is out of scope for your question.

Suggestion 2

You can create a Helper to get you this to work more modular.

Value publicStates

myApp.value('publicStates', function(){
    return {
      module: 'public',
      routes: [{
        name: 'login', 
        config: { 
          url: '/login'
        }
      }]
    };
});

Value privateStates

myApp.value('privateStates', function(){
    return {
      module: 'private',
      routes: [{
        name: 'suggestions', 
        config: { 
          url: '/suggestions'
        }
      }]
    };
});

The Helper

myApp.provider('stateshelperConfig', function () {
  this.config = {
    // These are the properties we need to set
    // $stateProvider: undefined
    process: function (stateConfigs){
      var module = stateConfigs.module;
      $stateProvider = this.$stateProvider;
      $stateProvider.state(module, {
        abstract: true,
        module: module
      });
      angular.forEach(stateConfigs, function (route){
        route.config.module = module;
        $stateProvider.state(module + route.name, route.config);
      });
    }
  };

  this.$get = function () {
    return {
      config: this.config
    };
  };
});

Now you can use the helper to add the state configuration to your state configuration.

myApp.config(['$stateProvider', '$urlRouterProvider', 
    'stateshelperConfigProvider', 'publicStates', 'privateStates',
  function ($stateProvider, $urlRouterProvider, helper, publicStates, privateStates) {
    helper.config.$stateProvider = $stateProvider;
    helper.process(publicStates);
    helper.process(privateStates);
}]);

This way you can abstract the repeated code, and come up with a more modular solution.

Note: the code above isn't tested