AJAX in JS Module Pattern

I'm creating an application using Module Pattern in JS. I've create two modules and I have this code:

var dataController = (function ()
var request = new XMLHttpRequest();

var getFilmes = function ()
request.onreadystatechange = function()
if(request.readyState === 4)
if(request.status === 200)
var obj = JSON.parse(request.responseText);
return obj;
else
console.log('An error occurred during your request: ' + request.status + ' ' + request.statusText);




request.open('Get', 'http://localhost:8080/api/filmes/5b8947446f506266bc522f38');
request.send();


return
filmes: function ()
return getFilmes();


;

)();

var controller = (function (dataCtrl)

var preencheFilmes = function()
var obj = dataCtrl.filmes();
console.log(obj);



return
init: function()
console.log("APP START");
preencheFilmes();

;

)(dataController, UIController);


controller.init();


The problem is that I can't get the response from AJAX when I'm calling preencheFIlmes in the "init". But I can get the result in the dataController.

Someone can help me? I'm learning how to work with this pattern.

Thank you so much.

1 Answer
1

Your function getFilmes() is asynchronous and doesn't return anything. A simple solution is to add a callback parameter like this:

getFilmes()

var getFilmes = function(callback)
request.onreadystatechange = function()
if(request.readyState === 4)
if(request.status === 200)
var obj = JSON.parse(request.responseText);
callback(obj); // <-- calls the callback function
else
...



...



Then you can pass an anonymous callback function when you want to get the results:

var preencheFilmes = function()
dataCtrl.filmes(function(obj)
console.log(obj);
);



Another option is to use the async/await feature, see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/async_function

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