I have a controller where I need to load content using ajax. While it's loading, I'd like a spinner to appear in the interim. The code looks something like the below:

```
<i class="fa fa-2x fa-spin fa-spinner" ng-show="isLoadingContent"></i>

```

And the corresponding js:

```
$scope.isLoadingContent = true;
$q.all(promises).then(function (values) {
    $scope.isLoadingContent = false;
    // more code - display returned data

```

However, the UI the spinner does not appear where/when I expect it to appear when I step through the code.

```
$scope.isLoadingContent = true;
debugger; // the spinner does not appear on the UI
$q.all(promises).then(function (values) {
    debugger; // the spinner finally does appear in the UI at this point
    $scope.isLoadingContent = false;
    // more code - display returned data

```

I have tried stepping through the code but came up short as to what's going on --
 and I am sure I am misunderstanding the sequence of events happening in the Event Loop and where the angular-cycle plays it's role in all of this. 

Is someone able to provide an explanation as to why the spinner is set to appear within the promise's method rather than where I set `$scope.isLoadingContent`? Is it not actually getting set but rather getting queue'd up in the event-loop's message-queue?

------------ EDIT ------------

I believe I came across an explanation as to what's going on. Thanks in large part to, @jcford and @istrupin.

So a little tidbit missing in the original post, the event firing the promise calls and the spinner update was actually based around a `$scope.$on("some-name", function(){...})` event - effectively a click-event that is triggered outside of my current controller's scope. I believe this means the $digest cycle doesn't work as it typically does because of where the event-origination is fired off. So any update in the `$on` function doesn't call $apply/$digest like it normally does, meaning I have to specifically make that $digest call. 

Oddly enough, I realize now that within the `$q.all()`, it must call `$apply` since, when debugging, I saw the DOM changes that I had expected. Fwiw.

tl;dr - call `$digest`.