How to handle ajax call in laravel controller functions

Question

I perform an ajax call to a laravel controller, but it seems not working. What can I do?

public function postSubmit($id) {//Gelen geornal id'si

    header('Content-Type: application/json');

    $uploaded = [];
    $allowed = ['jpg', 'png'];

    $succeeded = [];
    $failed = [];

    if(!empty($_FILES['dosya'])) {

           // It seems not entering here.. I want to save file here.

    }

When I write that in controller:

$allFiles = Input::all();
return $allFiles;

I get this in my console:

Object {ajax: "true", file: Array[1]}

How can I get my file in controller?

This is the script:

<script>

    document.getElementById('submit-button').addEventListener('click', function(e) {
        e.preventDefault();

        var f = document.getElementById('file_input'),

        app.uploader({
            files: f,
            processor: "{{ URL::route('category/post', array($category->id)) }}",

        });

    });


</script>

And I have getFormData and ajax function to get FormData and for a XMLHttpRequest.