jQuery Ajax Upload File php receives array even with out content

Question

It's working but on every submit I receive an array even tho a file is not even added to the file input (multifile input)

    postData = new FormData(this); 
    $.ajax({
        url: "/url",
        type: "POST",
        data: postData,
        cache: false,
        contentType: false,
        processData: false,
        success: function (data, textStatus, jqXHR) {
            if (data === "true") {
                window.location.replace("/url");
            } else {
                $(".errors").html(data);
            }
        },
        error: function (jqXHR, textStatus, errorThrown) {
            swal("Der opstod en fejl");
        }
    });

What i get from $_FILES is the following

Array
(
    [files] => Array
        (
            [name] => Array
                (
                    [0] => 
                )

            [type] => Array
                (
                    [0] => 
                )

            [tmp_name] => Array
                (
                    [0] => 
                )

            [error] => Array
                (
                    [0] => 4
                )

            [size] => Array
                (
                    [0] => 0
                )
        )
)

Is there a way where I can avoid this from happening?

Answer 1

Try adding required attribute to input type="file" element to prevent submission of form if no files selected by user

$("form").on("submit", function(e) {
  e.preventDefault();
  // do `$.ajax()` stuff
})

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js">
</script>
<form>
  <input type="file" name="files[]" multiple required />
  <input type="submit" />
</form>