Angular promise resolves inside function but not outside - angularjs

Question

I have a recursive function checking for some data every half second or so. The function returns a promise. Once I find the data, I want to resolve the promise and pass the data as the resolution. The problem is, the promise won't call .then() outside of the function. Here's the fiddle: http://jsfiddle.net/btyg1u0g/1/.
Here's the fiddle code:
Service:
myApp.factory('myService', function($q, $timeout) {
var checkStartTime = false;
var checkTimeout = 30000;
function checkForContent() {
var deferred = $q.defer();
// simulating an $http request here
$timeout(function () {
console.log("Checking...");
if (!checkStartTime) checkStartTime = new Date();
// this would normally be 'if (data)'
if ((new Date()) - checkStartTime > 3000) {
deferred.resolve("Finished check");
checkStartTime = false; // reset the timeout start time
} else {
// if we didn't find data, wait a bit and check again
$timeout(function () {
checkForContent();
}, 400);
}
}, 5);
// then is called in here when we find data
deferred.promise.then(function(message) {
console.log("Resolved inside checkForContent");
});
return deferred.promise;
}
return {
runCheck: function() {
return checkForContent()
}
}
});
Controller:
myApp.controller('MyCtrl', function ($scope, myService) {
$scope.name = 'Superhero';
// then is never called
myService.runCheck()
.then(function (message) {
console.log("Resolved outside checkForContent");
});
});

Answer 1

Check out this fiddle.
The outter $timeout function is named so it can be called from within itself.
$timeout(function inner() {
// ...
Then it is called recursively like this:
$timeout(function () {
inner();
}, 400);