Cordova / AngularJS工厂GET JSON XMLHttpRequest

Question

I've been trying to fetch a JSON from an api with a XMLHttpRequest inside a factory but it ends up returning undefined even though the logging inside it suggest that it should work just fine.

Here is my factory code

.factory('MyService', function(){
return {
    getJSON: function(path){
      var xhr = new XMLHttpRequest();
      xhr.open("Get", path, true);
      xhr.onreadystatechange = function(){
        if(xhr.readyState === 4){
          if(xhr.status === 200){
            console.log(JSON.parse(xhr.responseText)); // Displays a correct JSON object
            return JSON.parse(xhr.responseText); // Returns said object
          }else{
            return xhr;
          }
        }
      };
      xhr.send();
      }
    }
})

Here I call the service from my controller

$scope.test = MyService.getJSON("api url"); // Ends up as undefined

the console.log inside the factory triggers and displays the JSON correctly, how ever $scope.test ends up being undefined even though we return the exact same JSON to the $scope.test

If anybody has any idea why this isn't working, that would be great, thank you

Answer 1

It is because of the cross domain call you are doing. Either enable the cross origin call or do a normal http-promise! You should use the internet explorer as the browser.

I hope this helps : http://enable-cors.org/

1. https://docs.angularjs.org/api/ng/service/ $http

Answer 2

可能在半年前就解决了这个问题，问题是工厂没有返回承诺，而是在使用$ q将其变为承诺后，工厂开始按预期工作。