javascript - How to use FormData for ajax file upload -

this html i'm generating dynamically using drag , drop functionality.

<form method="post" id="contact" name="13" class="form-horizontal wpc_contact" novalidate="novalidate" enctype="multipart/form-data"> <fieldset>     <div id="legend" class="">         <legend class="">file demoe 1</legend>         <div id="alert-message" class="alert hidden"></div>     </div>      <div class="control-group">         <!-- text input-->         <label class="control-label" for="input01">text input</label>         <div class="controls">             <input type="text" placeholder="placeholder" class="input-xlarge" name="name">             <p class="help-block" style="display:none;">text_input</p>         </div>         <div class="control-group">  </div>         <label class="control-label">file button</label>          <!-- file upload -->          <div class="controls">             <input class="input-file" id="fileinput" type="file" name="file">         </div>     </div>     <div class="control-group">              <!-- button -->          <div class="controls">             <button class="btn btn-success">button</button>         </div>     </div> </fieldset> </form>  

this js code...

<script>     $('.wpc_contact').submit(function(event){         var formname = $('.wpc_contact').attr('name');         var form = $('.wpc_contact').serialize();                        var formdata = new formdata($(form)[1]);          $.ajax({             url : '<?php echo plugins_url(); ?>'+'/wpc-contact-form/resources/js/tinymce.php',             data : {form:form,formname:formname,ipadd:ipadd,formdata:formdata},             type : 'post',             processdata: false,             contenttype: false,             success : function(data){             alert(data);              }         });    } 

for correct form data usage need 2 steps.

preparations

you can give whole form formdata() processing

var form = $('form')[0]; // need use standard javascript object here var formdata = new formdata(form); 

or specify exact data formdata()

var formdata = new formdata(); formdata.append('section', 'general'); formdata.append('action', 'previewimg'); // attach file formdata.append('image', $('input[type=file]')[0].files[0]);  

sending form

ajax request jquery looks this:

$.ajax({     url: 'your url here',     data: formdata,     type: 'post',     contenttype: false, // needed, don't omit (requires jquery 1.6+)     processdata: false, // needed, don't omit     // ... other options success , etc }); 

after send ajax request submit regular form enctype="multipart/form-data"

update: request cannot work without type:"post" in options, cause files must sent via post request.

note: contenttype: false available from jquery 1.6 onwards