Upload files with AJAX

Question

I’m participating in a project but I can’t upload files using ajax.

MODEL

    <?php // You need to add server side validation and better error handling here

$data = array();

if(isset($_GET['files']))
{ 
  $error = false;
  $files = array();

  $uploaddir = $_SERVER['DOCUMENT_ROOT'] . '/SISPESQ/Sispesq/public/uploads/arquivos/';
  foreach($_FILES as $file)
  {
    if(move_uploaded_file($file['tmp_name'], $uploaddir .basename($file['name'])))
    {
      $files[] = $uploaddir .$file['name'];
    }
    else
    {
        $error = true;
    }
  }
  $data = ($error) ? array('error' => 'There was an error uploading your files') : array('files' => $files);
}
else
{
  $data = array('success' => 'Form was submitted', 'formData' => $_POST);
}

echo json_encode($data);

?>

As for the AJAX

$(function () {

var form;
$('#arquivo').change(function (event) {
    form = new FormData();
    form.append('arquivo', event.target.files[0]); // para apenas 1 arquivo
    //var name = event.target.files[0].content.name; // para capturar o nome do arquivo com sua extenção
});

$('#btnEnviar').click(function () {
    $.ajax({
        url: '/SISPESQ/Sispesq/app/actions/inserirEdital.php?arquivo', // Url do lado server que vai receber o arquivo
        data: form,
        processData: false,
        contentType: false,
        type: 'POST',
        success: function (data) {
            if(data){
                $("#alert").html(data).css({"display": "block"}).addClass('alert alert-success');
            } else {
                $("#alert").html(data).css({"display": "block"}).addClass('alert alert-danger');
            }
        },
        error: function(data){
            $("#alert").html(data).css({"display": "block"}).addClass('alert alert-danger');
        }
    });
});
 });

VIEW

<label>Nome:</label>
              <input type="text" id="nome" name="nome" class="form-control" placeholder="Digite aqui o nome do edital" required/>
            </div>
            <input type="file" id="arquivo" name="arquivo" accept="application/pdf" required/>
            <p class="help-block">Selecione o arquivo .pdf</p>
<button type="submit" id="btnEnviar" class="btn btn-primary pull-right">Salvar</button>

In case it comes up error: I don’t know why you’re doing this...