Run a controller function whenever a view is opened/shown

Question

I'm building an app with angular+ionic that uses a classic three-button menu at the bottom with three ion-tabs in it. When a user clicks a tab, that template opens through ui-router.

I have states like this:

$stateProvider
  .state('other', {
    url: "/other",
    abstract: true,
    templateUrl: "templates/other/other.html"
})

In the template I do something like:

<ion-nav-view name="other" ng-init="doSomething()"></ion-nav-view>

I'm aware that I can write the doSomething() function in my controller and just call it manually there. That gives me the same problem though. I can't seem to figure out how to call the doSomething() function more than once, whenever somebody opens that view.

Right now, the doSomething() function gets called just fine, but only the first time that view/tab gets opened by the user. I'd like to call a function (to update geolocation) whenever a user opens that view or tab.

What would be a correct way to implement that?

Answer 1

By default, your controllers were cache and that is why your controller only fired once. To turn off caching for a certain controller you have to modify your .config(..).state and set the cache option to false. eg :

  .state('myApp', {
    cache: false,
    url: "/form",
    views: {
      'menuContent': {
        templateUrl: "templates/form.html",
        controller: 'formCtrl'
      }
    }
  })

for further reading please visit http://ionicframework.com/docs/api/directive/ionNavView/

Answer 2

Following up on the answer and link from AlexMart, something like this works:

.controller('MyCtrl', function($scope) {
  $scope.$on('$ionicView.enter', function() {
     // Code you want executed every time view is opened
     console.log('Opened!')
  })
})

Answer 3

If you have assigned a certain controller to your view, then your controller will be invoked every time your view loads. In that case, you can execute some code in your controller as soon as it is invoked, for example this way:

<ion-nav-view ng-controller="indexController" name="other" ng-init="doSomething()"></ion-nav-view>

And in your controller:

app.controller('indexController', function($scope) {
    /*
        Write some code directly over here without any function,
        and it will be executed every time your view loads.
        Something like this:
    */
    $scope.xyz = 1;
});

Edit: You might try to track state changes and then execute some code when the route is changed and a certain route is visited, for example:

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

You can find more details here: State Change Events.

Answer 4

I faced at the same problem, and here i leave the reason of this behavior for everyone else with the same issue.

View LifeCycle

In order to improve performance, we've improved Ionic's ability to cache view elements and scope data. Once a controller is initialized, it may persist throughout the app’s life; it’s just hidden and removed from the watch cycle. Since we aren’t rebuilding scope, we’ve added events for which we should listen when entering the watch cycle again.

To see full description and $ionicView events go to: http://ionicframework.com/blog/navigating-the-changes/

Answer 5

Why don't you disable the view cache with cache-view="false"?

In your view add this to the ion-nav-view like that:

<ion-nav-view name="other" cache-view="false"></ion-nav-view>

Or in your stateProvider:

$stateProvider.state('other', {
   cache: false,
   url : '/other',
   templateUrl : 'templates/other/other.html'
})

Either one will make your controller being called always.