angular js http get

Question

I am not too familiar with angularJS and am having trouble trying to use http.get(). I am completing a QR scan and the text that is received from the QR code will then be placed into my url. The problem that I am receiving is that the http.get() is executing before the scan is being completed. Therefore returning "Error". How can I make this so that the http.get(url) is executed only after the $scope.QRScan() function is completed.

  $scope.QRscan(); /// Want to finish first

  var params = "?number=" + $scope.QRText;
  params += "&action=ci";

  var url = "http://test/test.php" + params;

  var promise = $http.get(url);

  promise.then(
    function(payload) {
      var r = payload.data;

      if (r.status.toString() == '1') {
        var alertPopup = $ionicPopup.alert({
          title: ' successful ',
        });
      } else {
        var alertPopup = $ionicPopup.alert({
          title: 'Error',
        });

      };
    });

QRScan()

  $scope.QRscan = function () {
  $cordovaBarcodeScanner.scan().then(function (qrData) {
  }, function (error) {
    var alertPopup = $ionicPopup.alert({
      title: 'There was an error scanning the QR code.',
    });
  });
     $scope.QRText = qrData.text;
};

Answer 1

$http.get() is asynchronous

you can write it like this:

function getData() {
  return $http.get(url)
    .then(function(data) {
    // this is where we can manipulate your data
    // set to $scope object/whatever
    // because its async, we need to use a promise (or callback) to wait for
    // the response from your get request
  })
  .catch(function(err) {
    // if err, console.log(err)
  })
}

There are a couple ways to do this, the above is under 'Shortcut Methods' in the following angular docs: https://docs.angularjs.org/api/ng/service/$http