Why does AngularJS with ui-router keep firing the $stateChangeStart event?

StackOverflow https://stackoverflow.com//questions/25065699

  •  23-12-2019
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Question

I'm trying to block all ui-router state changes until I've authenticated the user:

$rootScope.$on('$stateChangeStart', function (event, next, toParams) {
  if (!authenticated) {
    event.preventDefault()
    //following $timeout is emulating a backend $http.get('/auth/') request
    $timeout(function() {
      authenticated = true
      $state.go(next,toParams)
    },1000)
  }
})

I reject all state changes until the user has been authenticated, but if I go to an invalid URL that uses the otherwise() configuration, I get an infinite loop with a message:

Error: [$rootScope:infdig] 10 $digest() iterations reached. Aborting!
Watchers fired in the last 5 iterations: [["fn: $locationWatch; newVal: 7; oldVal: 6"],["fn: $locationWatch; newVal: 8; oldVal: 7"],["fn: $locationWatch; newVal: 9; oldVal: 8"],["fn: $locationWatch; newVal: 10; oldVal: 9"],["fn: $locationWatch; newVal: 11; oldVal: 10"]]

Below is my SSCCE. Serve it up with python -m SimpleHTTPServer 7070 and go to localhost:7070/test.html#/bar to see it explode in your face. Whereas directly navigating to the only valid angularjs location does not blow up localhost:7070/test.html#/foo:

<!doctype html>
  <head>
    <script src="//ajax.googleapis.com/ajax/libs/jquery/1.11.0/jquery.js"></script>
    <script src="//ajax.googleapis.com/ajax/libs/angularjs/1.2.15/angular.js"></script>
    <script src="//cdnjs.cloudflare.com/ajax/libs/angular-ui-router/0.2.10/angular-ui-router.min.js"></script>
  </head>
  <body ng-app="clientApp">
    <div ui-view="" ></div>

    <script>
      var app = angular.module('clientApp', ['ui.router'])

      var myRouteProvider = [
                '$stateProvider', '$urlRouterProvider',
        function($stateProvider,   $urlRouterProvider) { 
          $urlRouterProvider.otherwise('/foo');
          $stateProvider.state('/foo', {
            url: '/foo',
            template: '<div>In Foo now</div>',
            reloadOnSearch: false
          })
        }]
      app.config(myRouteProvider)

      var authenticated = false
      app.run([
                 '$rootScope', '$log','$state','$timeout',
        function ($rootScope,   $log,  $state,  $timeout) {
          $rootScope.$on('$stateChangeStart', function (event, next, toParams) {
            if (!authenticated) {
              event.preventDefault()
              //following $timeout is emulating a backend $http.get('/auth/') request
              $timeout(function() {
                authenticated = true
                $state.go(next,toParams)
              },1000)
            }
          })
        }
      ])
    </script>
  </body>
</html>

Is there an alternative method I should use to accomplish this authentication blocking? I do realize this authentication blocking is client side only. I'm not showing the server side of things in this example.

Was it helpful?

Solution 2

Fakeout. This is an interaction issue between $urlRouterProvider and $stateProvider. I shouldn't be using $urlRouterProvider for my otherwise. I should be using something like:

$stateProvider.state("otherwise", {
    url: "*path",
    template: "Invalid Location",
    controller: [
              '$timeout','$state',
      function($timeout,  $state ) {
        $timeout(function() {
          $state.go('/foo')
        },2000)
      }]
});

Or even a transparent'ish redirect:

$stateProvider.state("otherwise", {
    url: "*path",
    template: "",
    controller: [
              '$state',
      function($state) {
        $state.go('/foo')
      }]
});

Altogether now:

<!doctype html>
  <head>
    <script src="//ajax.googleapis.com/ajax/libs/jquery/1.11.0/jquery.js"></script>
    <script src="//ajax.googleapis.com/ajax/libs/angularjs/1.2.15/angular.js"></script>
    <script src="//cdnjs.cloudflare.com/ajax/libs/angular-ui-router/0.2.10/angular-ui-router.min.js"></script>
  </head>
  <body ng-app="clientApp">
    <div ui-view="" ></div>

    <script>
      var app = angular.module('clientApp', ['ui.router'])

      var myRouteProvider = [
                '$stateProvider',
        function($stateProvider) { 

          $stateProvider.state('/foo', {
            url: '/foo',
            template: '<div>In Foo now</div>',
            reloadOnSearch: false
          })

          $stateProvider.state("otherwise", {
              url: "*path",
              template: "",
              controller: [
                        '$state',
                function($state) {
                  $state.go('/foo')
                }]
          });
        }]
      app.config(myRouteProvider)

      var authenticated = false
      app.run([
                 '$rootScope', '$log','$state','$timeout',
        function ($rootScope,   $log,  $state,  $timeout) {
          $rootScope.$on('$stateChangeStart', function (event, next, toParams) {
            if (!authenticated) {
              event.preventDefault()
              //following $timeout is emulating a backend $http.get('/auth/') request
              $timeout(function() {
                authenticated = true
                $state.go(next,toParams)
              },1000)
            }
          })
        }
      ])
    </script>
  </body>
</html>

OTHER TIPS

Looks like this is a bug with ui-router when you use the combination of $urlRouterProvider.otherwise("/foo) with the $stateChangeStart.

Issue - https://github.com/angular-ui/ui-router/issues/600

Frank Wallis provides a nice workaround, use the longer form of the otherwise method that takes a function as an argument:

$urlRouterProvider.otherwise( function($injector, $location) {
            var $state = $injector.get("$state");
            $state.go("app.home");
        });

Nice work Frank!

I also had this issue. Below is the code to workaround, which inspired by angular-permission project.

The main concept is to add a flag($$finishAuthorize) into state manually, and break the infinite loop by this flag. Another point we need to be aware is the {notify: false} option of $state.go, and broadcast "$stateChangeSuccess" event manually.

$rootScope.$on('$stateChangeStart', function (event, toState, toParams, fromState, fromParams) {
    if (toState.$$finishAuthorize) {
        return;
    }
    if (!authenticated) {
        event.preventDefault();
        toState = angular.extend({'$$finishAuthorize': true}, toState);

        // following $timeout is emulating a backend $http.get('/auth/') request
        $timeout(function() {
            authenticated = true;
            $state.go(toState.name, toParams, {notify: false}).then(function() {
                $rootScope.$broadcast('$stateChangeSuccess', toState, toParams, fromState, fromParams);
            });
        },1000)
    }
);

I also had this issue. Turns out it was the code that they suggested to make a trailing slash optional at https://github.com/angular-ui/ui-router/wiki/Frequently-Asked-Questions#how-to-make-a-trailing-slash-optional-for-all-routes

$urlRouterProvider.rule(function ($injector, $location) {
  var path = $location.url();

  console.log(path);
  // check to see if the path already has a slash where it should be
  if (path[path.length - 1] === '/' || path.indexOf('/?') > -1) {
    return;
  }

  if (path.indexOf('?') > -1) {
    return path.replace('?', '/?');
  }

  return path + '/';
});

changed this to

$urlRouterProvider.rule(function ($injector, $location) {
  var path = $location.url();
  // check to see if the path already has a slash where it should be
  if (path[path.length - 1] === '/' || path.indexOf('/?') > -1) {
    return;
  }
  if (path.indexOf('?') > -1) {
    $location.replace().path(path.replace('?', '/?'));
  }
  $location.replace().path(path + '/');
});

not returning the new path and just replacing it doesn't trigger a StateChangeStart

Try changing your run block to this:

    app.run([
             '$rootScope', '$log','$state','$interval',
    function ($rootScope,   $log,  $state,  $interval) {
      var authenticated = false;
      $rootScope.$on('$stateChangeStart', function (event, next, toParams) {
        if (!authenticated) {
          event.preventDefault()
          //following $timeout is emulating a backend $http.get('/auth/') request
        }
      })


      var intervalCanceller = $interval(function() {
        //backend call
        if(call succeeds & user authenticated) {
          authenticated = true;
          $interval.cancel(intervalCanceller);
          $state.go(next, toParams);
        }
      }, 3000);
    }
  ])

I tried the above solutions, with varying degrees of success (am building an Ionic cordova application). At one point I managed to not get infinite loops and the state would change but I was left with a blank view. I added { reload:true } and it seems to help. I tried with { notify:false } and { notify: true } and that did not help.

I ended up using most of the answer from: https://stackoverflow.com/a/26800804/409864

$rootScope.$on('$stateChangeStart', function (event, toState, toParams, fromState, fromParams) {

  // Do not redirect if going to an error page
  if (toState.name === 'app.error') {
    return;
  }

  // Do not redirect if going to the login page
  if (toState.name === 'app.login') {
    return;
  }

  // Do not redirect if there is a token present in localstorage
  var authData = localstorage.getItem('auth');
  if (authData.token) {
    return;
  }

  // We do not have a token, are not going to the login or error pages, time to redirect!
  event.preventDefault();
  console.debug('No auth credentials in localstorage, redirecting to login page');
  $state.go('engineerApp.home', {}, {reload: true}); // Empty object is params
});
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