Constantly running service while in app - angularjs

Question

I am developing an app that pushes user's geolocation to the server (with regards to permissions, of course).Currently, when the user navigates to the account page, a method is invoked to push their geolocation to the server.Instead, I would like a service (if that's the best method) to run while the app is running that will push the geolocation. This means that the location held for the user will always be up to date and not just updated when the account page is visited.
There is a checkbox on the account page where they select if they want to share their geolocation or not.I have a $watcher on the checkbox...
$scope.$watch("account.shareLocation", function(newValue, oldValue) {
if (newValue) {
locationService.pushLocation(userPosition);
} else {
locationService.pushLocation(null);
}
});
So, if the user selects to share their location (newValue === true) then, pushLocation() should be constantly invoked with the userPosition until the value of account.shareLocation (the checkbox) is altered otherwise.

Answer 1

I made a small example here: https://jsfiddle.net/ojzdxpt1/2/
You have your main controller that inits the service if the user has allowed it (I also added a mock $timeout of them unchecking it).
var app = angular.module('TestApp', []);
app.controller('TestController', function($scope, $timeout, LocationService) {
console.log('app init');
//-- on checkbox change and/or app init;
var trackLocation = true;
if (trackLocation) {
LocationService.start();
//-- imitate them turning the service off
$timeout(function() {
console.log('stop tracking location');
LocationService.stop();
},10000);
}
});
Now for your service you could do something like this:
app.service('LocationService', function($interval) {
var int;
return {
start: function() {
int = $interval(this.saveLocation,3000);
},
stop: function() {
$interval.cancel(int);
},
saveLocation: function() {
console.log('save location');
}
}
});