Question

in order to check if the user has provided all the permissions i need for my app, I do it so:

/*Solo hacemos la peticion si el checkbox estaba desmarcado. Nota: esta funcion asume que solo hay un checkbox en el dom*/
if($('input:checkbox').prop('checked')){
    FB.login(function(response){
             console.log(response.status);
            if (response.status == 'connected') {
            hi   /* Entonces listo */
            }else{
                 /* Entonces cancelamos el checkbox */
                 $('input:checkbox').removeAttr('checked');
            }
    }, { scope: 'publish_stream' });
}

This way:

• if user did it allready: a popup is opened for less than a second

• if user didnt yet: the permission dialog is shown

Question is: how can i prevent the dialog to be opened (maybe running it in the background) in the first case?

Answer 1

You cannot stop a popup when you use FB.login.

Either use a server side authentication or use FB.getLoginStatus to prevent popup in first case.

FB.getLoginStatus allows you to determine if a user is logged in to
Facebook and has authenticated your app

Refer Facebook docs

A snippet from the above reference link,

FB.getLoginStatus(function(response) {
  if (response.status === 'connected') {
    // the user is logged in and has authenticated your
    // app, and response.authResponse supplies
    // the user's ID, a valid access token, a signed
    // request, and the time the access token 
    // and signed request each expire
    var uid = response.authResponse.userID;
    var accessToken = response.authResponse.accessToken;
  } else if (response.status === 'not_authorized') {
    // the user is logged in to Facebook, 
    // but has not authenticated your app
  } else {
    // the user isn't logged in to Facebook.
  }
 });

This is what you need.

Edit: (after OP’s comment)

May be facebook is caching old result.
From the same link I mentioned above,

Roundtrips to Facebook’s servers

To improve the performace of your application, not every call to check
the status of the user will result in request to Facebook’s servers.
Where possible, the response is cached. The first time in the current
browser session that FB.getLoginStatus is called, or the JD SDK is
init’d with status: true, the response object will be cached by the
SDK. Subsequent calls to FB.getLoginStatus will return data from this
cached response.

This can cause problems where the user has logged into (or out of)
Facebook since the last full session lookup, or if the user has
removed your application in their account settings.

To get around this, you call FB.getLoginStatus with the second
parameter set to true to force a roundtrip to Facebook – effectively
refreshing the cache of the response object.

FB.getLoginStatus(function(response) {
      // this will be called when the roundtrip to Facebook has completed
    }, true);

If you call FB.getLoginStatus on every page load, be careful not to
set this parameter for each as it will significantly increase the
number of requests to Facebook’s servers, and thus decrease the
performace of your application.