unable to update the input field once the value is dropped to that input field value

i am using jquery builder in my ember app. i m using jquery drag and drop function to drop the value to the input field . my drag nd drop functionality is working fine but once the value is dropped to the input field of the query builder and then upon saving i m getting this error "Cannot read property 'condition' of null". This eventually means that particular input fieldis not accepting the drpped value. how to fix this issue??

my code in controller:

$('#buildQuery').on('dragleave', function(event) {
  if(event.target.className == "form-control"){
  $('.rule-value-container > input[name='+event.target.name+']').val("");
  $('.rule-value-container > input[name='+event.target.name+']').val("item name");
  }
});