title: Krajee Bootstrap fileinput how can i change the uploadExtraData dynamically
body: <p>Hi Am using Krajee Bootstrap fileinput , i need to change the <code>uploadExtraData</code> dynamically on submitting the form. So i made it as a call back function. But it doesn't work for me. As i think <code>uploadExtraData</code> callback function work at on initialization only.</p>
  
  <p>here is my code</p>
  
  <pre><code>$(".file-loading").fileinput({
       uploadUrl: document.location.origin + "/discussions/add",
       uploadAsync: false,
       uploadExtraData:getFormData(),
   });
  
  function getFormData(){
      var project_id = $("#DiscussionProjectId").val();
      var discussion_title = $("#DiscussionDiscussionTitle").val();
      var comment = $('#discussionComment').attr('value');
      var data = {
          project_id:project_id,
          discussion_title:discussion_title,
          comment:comment
      };
      return data;
  }
  </code></pre>
  
  <p>Am doing to save the input files and data on form submit only.</p>