jQuery drag’n’drop events chronology


When I was writing (learning jQuery) Solitaire game, I faced lack of documentation on drag-n-drop event’s order. So I made simple JavaScript code to investigate this:

$(function() {
    $( "#draggable" ).draggable({
      create: function( event, ui ) {console.log('DRG create');},
      drag: function( event, ui ) {console.log('DRG drag');},
      start: function( event, ui ) {console.log('DRG start');},
      stop: function( event, ui ) {console.log('DRG stop');},
      revert: function( event, ui ) {console.log('DRG revert'); return true;},

    $( "#droppable" ).droppable({
      drop: function( event, ui ) {console.log('DRP drop');},
      over: function( event, ui ) {console.log('DRP over');},
      out: function( event, ui ) {console.log('DRP out');},
      deactivate: function( event, ui ) {console.log('DRP deactivate');},
      activate: function( event, ui ) {console.log('DRP activate');},
      create: function( event, ui ) {console.log('DRP create');}
    $('#draggable').on('mousedown', function(){
      console.log('DRG M mousedown');
    $('#draggable').on('mouseup', function(){
      console.log('DRG M mouseup');
    $('#draggable').on('mouseenter', function(){
      console.log('DRG M mouseenter');
    $('#draggable').on('hover', function(){
      console.log('DRG M hover');
    $('#draggable').on('mouseleave', function(){
      console.log('DRG M mouseleave');
    $('#draggable').on('mouseout', function(){
      console.log('DRG M mouseout');
    $('#draggable').on('mouseclick', function(){
      console.log('DRG M mouseclick');

    $('#droppable').on('mousedown', function(){
      console.log('DRP M mousedown');
    $('#droppable').on('mouseup', function(){
      console.log('DRP M mouseup');
    $('#droppable').on('mouseenter', function(){
      console.log('DRP M mouseenter');
    $('#droppable').on('hover', function(){
      console.log('DRP M hover');
    $('#droppable').on('mouseleave', function(){
      console.log('DRP M mouseleave');
    $('#droppable').on('mouseout', function(){
      console.log('DRP M mouseout');
    $('#droppable').on('mouseclick', function(){
      console.log('DRP M mouseclick');

Working demo on JSFiddle – https://jsfiddle.net/y5ykm415/4/

So, quick summary of events order:

  1. Draggable element on mouse click (mousedown) executes drag start event and actual dragging begins
  2. All droppable elements activate an wait for droppables.
  3. Draggable’s drag event executes again and again on each, smallest mouse movement.
  4. When draggable reaches droppable and meets tolerance and accept conditions, it(draggable) can be dropped on droppable.
  5. After mouse button is realeased (mouseup event) and if draggable successfully dropped on droppable drop event fires.
  6. Then all droppables will deactivate.
  7. If draggable was not dropped on droppable – it can stay or return back to place depending on revert option.
  8. Draggable stops.

*Until mouse doesn’t move (after drop) mouseleave, mouseout & mousenter events won’t fire (even if elements will move from/to mouse).

Here I drawed a diagram of events over time of one drag’n’drop:


*All above was tested on Google’s Chrome. Can be some minor variations on others.

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