Promises

promises_real_example.js

// real example
$ionicLoading.show();
API.post(url, postObject, headers).then(() => {
    $state.go(homeStateName);
    $ionicPopup.alert({
        template: 'Some text'
    });
}).then($ionicLoading.hide).catch($ionicLoading.hide);


// Okay, that might be a little confusing, let me briefly explain:

/* code for start loader (spinner) */
API.post(url, postObject, config).then((resolve) => { // arrow function (ES6)
    // do something if success, for example show popup (modal), or change the location or update some info
})
    .then(/* function for hiding loader anyway (spinner) */)
    .catch(/* function for hiding loader anyway (spinner) */);
// P.S. 'API' is my own AngularJS service, for this example you just need to know that 'API' returns a Promise