Ajax file upload in Wordpress - can't pass FormData

Question

I\'ve made a script which uses $.ajax and FormData to pass two form objects to PHP. One form object is a text and the other is a file. It worked well as a stand-alone script

Answer 1

I added

 dataType: 'json'

and it helps. Full listing of your code of Ajax call:

jQuery.ajax({
    type: 'POST',
    url: fiuajax.ajaxurl,
    data: {
        action: 'fiu_upload_file',
        security: fiuajax.security,
        data: fd,
        dataType: 'json',
        contentType: false,
        processData: false,
    },
    success: function(response){
        var dataObj = jQuery.parseJSON(response);
        if(dataObj.message == 'error') {
            jQuery('.fiu_validation').html('The following error occured: '+dataObj.desc);
        }
        else if(dataObj.message == 'success') {
            jQuery('.fiu_file').val('');
        }
        console.log(response);
    }
});