php - submit form via jquery FormData -

i trying upload file using jquery. here's form:

<form id="upload_data" class="project" enctype="multipart/form-data" method="post">  <select id="project_id" name="project_id">    <option value="1">1</option>     <option value="2">2</option>  </select>   <input  type="file" id="data" name="data" />  <input type="hidden" name="user_id" id="user_id" value="12" required>  <button type="submit" id="ajax" class="btn btn-primary">submit</button> </form> 

here's jquery part:

$('#upload_data').submit( function( e ) {          var form = $('form');         var formdata = new formdata();                  $.each($(':input', form ), function(i, fileds){                    formdata.append($(fileds).attr('name'), $(fileds).val());                });                  $.each($('input[type=file]',form )[0].files, function (i, file) {                    formdata.append(file.name, file);                });  $.ajax( {       url: '../controllers/process.php',       type: 'post',       enctype: 'multipart/form-data',       data: formdata,       processdata: false,       contenttype: false,       success: function(data)         {             alert(data);         },         error: function(data)         {             alert(data);          }     } );      }); 

the problem getting empty post values in process.php:

if (isset($_post['project_id']) , isset($_post['user_id'])){    //process  }else{ echo 'no post data'; } 

it return 'no post data' (but in console, can see data has been posted it's not case in server.). missing here?

you can use ajaxform/ajaxsubmit functions ajax form plugin or jquery serialize function.

jquery ajax submit form

and

how send formdata objects ajax-requests in jquery?