在php中使用ajax提交multipart / form-data为null

Question

I have this kind of form: method="post" enctype="multipart/form-data"

Everytime the form is submitted via ajax

$("#openTicketSubmit").click(function(){
    var support_ticket_form_data = new FormData($("#support_ticket_form"));
    $.ajax({
        type: "POST",
        url: "{$systemurl}submit_ticket.php",
        data: support_ticket_form_data,
        contentType: 'multipart/form-data',
        success: function(results){
            console.log(results);
        },
        error( xhr, ajaxOptions, thrownError ){
            console.log( thrownError );
        }
    });
});

It got an error: jquery.min.js:4 Uncaught TypeError: Illegal invocation and then in the server side (php) the $_POST is null.

Please somebody help me.

Answer 1

To do a multipart/form-data request with jQuery.ajax, contentType and processData needs to be set to false.

Also the FormData constructor takes a form object not a jquery one

var support_ticket_form_data = new FormData($("#support_ticket_form")[0]);