DataTransfer.dropEffect

The DataTransfer.dropEffect property controls the feedback (typically visual) the user is given during a drag and drop operation. It will affect which cursor is displayed while dragging. For example, when the user hovers over a target drop element, the browser's cursor may indicate which type of operation will occur.

When the DataTransfer object is created, dropEffect is set to a string value. On getting, it returns its current value. On setting, if the new value is one of the values listed below, then the property's current value will be set to the new value and other values will be ignored.

For the dragenter and dragover events, dropEffect will be initialized based on what action the user is requesting. How this is determined is platform specific, but typically the user can press modifier keys such as the alt key to adjust the desired action. Within event handlers for dragenter and dragover events, dropEffect should be modified if a different action is desired than the action that the user is requesting.

For the drop and dragend events, dropEffect will be set to the action that was desired, which will be the value dropEffect had after the last dragenter or dragover event. In a dragend event, for instance, if the desired dropEffect is "move", then the data being dragged should be removed from the source.

Syntax

dataTransfer.dropEffect;

Values

A DOMString representing the drag operation effect. The possible values are:

copy
A copy of the source item is made at the new location.
move
An item is moved to a new location.
link
A link is established to the source at the new location.
none
The item may not be dropped.

Assigning any other value to dropEffect has no effect and the old value is retained.

Example

This example shows the use of the dropEffect and effectAllowed properties.

HTML Content

<div>
  <p id="source" ondragstart="dragstart_handler(event);" draggable="true">
    Select this element, drag it to the Drop Zone and then release the selection to move the element.
  </p>
</div>
<div id="target" ondrop="drop_handler(event);" ondragover="dragover_handler(event);">Drop Zone</div>

CSS Content

div {
  margin: 0em;
  padding: 2em;
}

#source {
  color: blue;
  border: 1px solid black;
}

#target {
  border: 1px solid black;
}

JavaScript Content

function dragstart_handler(ev) {
  console.log("dragStart: dropEffect = " + ev.dataTransfer.dropEffect + " ; effectAllowed = " + ev.dataTransfer.effectAllowed);

  // Add this element's id to the drag payload so the drop handler will
  // know which element to add to its tree
  ev.dataTransfer.setData("text", ev.target.id);
  ev.dataTransfer.effectAllowed = "move";
}

function drop_handler(ev) {
  console.log("drop: dropEffect = " + ev.dataTransfer.dropEffect + " ; effectAllowed = " + ev.dataTransfer.effectAllowed);
  ev.preventDefault();

  // Get the id of the target and add the moved element to the target's DOM
  var data = ev.dataTransfer.getData("text");
  ev.target.appendChild(document.getElementById(data));
}

function dragover_handler(ev) {
  console.log("dragOver: dropEffect = " + ev.dataTransfer.dropEffect + " ; effectAllowed = " + ev.dataTransfer.effectAllowed);
  ev.preventDefault();
  // Set the dropEffect to move
  ev.dataTransfer.dropEffect = "move"
}

Specifications

Specification Status Comment
WHATWG HTML Living Standard
The definition of 'dropEffect' in that specification.
Living Standard  
HTML5.1
The definition of 'dropEffect' in that specification.
Recommendation Initial definition

Browser compatibility

  
Feature Chrome Edge Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support 4(Yes) 3.5 10 12 3.1
  
Feature Android Android Webview Chrome for Android Edge Firefox Mobile (Gecko) Firefox OS IE Mobile Opera Mobile Safari Mobile
Basic support No support No support No support(Yes) No support No support 10 No support No support

See also

Document Tags and Contributors

 Contributors to this page: erikadoyle, Dave-Choi, Sebastianz, AFBarstow, teoli
 Last updated by: erikadoyle,