$ http获取请求未及时在angularjs / ionic中完成

Question

I'm trying to fill options with values instead of undefined, but seems to keep getting the values after the select box has finished loading.

HTML:

<label for="to">Destination:
    <select id="to" name="to" ng-model="toSelected" data-ng-options="stop.stop_id as stop.name for stop in stops">
      <option value="">Choose a Destination</option>
    </select>
  </label>

AngularJS Factory:

 .factory('DataFactory', ['$http', function ($http) {


// Might use a resource here that returns a JSON array
return {

  getAllStops: function () {
    return $http({
      method: 'GET',
      url: 'https://myAPIURL.com/api',
      headers: {
        "Accept": "application/json",
        "X-Mashape-Key": "KEYKEYKEYKEYKEYKEYKEYKEYKEYKEYKEY"
      }
    }).then(function (res) {
      return res;
    })
  },
      getAllRoutes: function () {
      return someresult similar to the above function;
  // more functions. 
  }

AngularJS Controller:

  .controller('MainCtrl', ['$scope', '$http', '_', 'DataFactory', function ($scope, $http, _, DataFactory) {

$scope.fromSelected = "";
$scope.toSelected = "";

DataFactory.getAllStops().then(function successCallback(res) {
  console.log(res);
  $scope.stops = res.data;

}, function errorCallback(err) {
  console.log("error: ");
  console.log(err);
});

$scope.changed = function (location, destination) {
console.log($scope.stops);
  $scope.possibleRoutes = DataFactory.getPossibleRoutes(location, destination);

Answer 1

Consider initializing $scope.stops with placeholder data (ie $scope.stops = [{stop_id: false, name: 'Loading'}] .

Alternatively, you could use an ng-if to load the select box when your data is done loading.

Ex.

<div class="input" ng-if="stops"> 
  <label for="to">Destination:
    <select id="to" name="to" ng-model="toSelected" data-ng-options="stop.stop_id as stop.name for stop in stops">
       <option value="">Choose a Destination</option>
    </select>
  </label>
</div>

And in the controller nothing really changes. This assumes you do not initialize $scope.stops

DataFactory.getAllStops().then(function successCallback(res) {
  console.log(res);
  $scope.stops = res.data;
}, function errorCallback(err) {
  console.log("error: ");
  console.log(err);
  // TODO: Gracefully degrade
});

Another option would be to do the above while showing a loading state while $scope.stops is undefined. That would work similarly to above.

Answer 2

Your factory isn't returning a promise as expected in your factory. Remove then 'then' from the factory as follow to return a promise, or the http request.:

 .factory('DataFactory', ['$http', function ($http) {


// Might use a resource here that returns a JSON array
return {

  getAllStops: function () {
    return $http({
      method: 'GET',
      url: 'https://myAPIURL.com/api',
      headers: {
        "Accept": "application/json",
        "X-Mashape-Key": "KEYKEYKEYKEYKEYKEYKEYKEYKEYKEYKEY"
      }
    })
  },
      getAllRoutes: function () {
      return someresult similar to the above function;
  // more functions. 
  }

The controller is handling the promise correctly once that change is made assuming you're getting a response.

Also, verify that "stop_id" is on the actual response. As opposed to... stopID or something. if stopID is there, but you're pulling stop.stop_id, it would show as undefined.