HTML ondragend Event Attribute

Description

The ondragend HTML event attribute fires when the user has finished dragging an element or text selection. It is one of the four drag-and-drop events that can be used to handle different stages of a drag-and-drop operation.

To use the ondragend event attribute, simply assign a JavaScript function to it. When the user finishes dragging the element, the function will be executed. The function will receive an event object as an argument, which contains information about the drag-and-drop event.

Here is an example of how to use the ondragend event attribute:

<div draggable="true" ondragend="myDragEndFunction()">
  Drag me!
</div>

<script>
function myDragEndFunction(event) {
  // Do something when the user finishes dragging the element
}
</script>

The ondragend event can be used for a variety of purposes, such as:

Updating the UI when the user has finished dragging an element to a new location.
Performing some action on the dragged element, such as saving it to a database or uploading it to a server.
Preventing the user from dropping the element on certain targets.

Here are some examples of how the ondragend event can be used:

A to-do list app could use the ondragend event to update the position of a to-do item when the user drags it to a new location in the list.
A file explorer app could use the ondragend event to upload a file to a server when the user drops it on the upload area.
A game could use the ondragend event to prevent the user from dropping a game piece on a certain location on the game board.

In HTML5, seven event attributes were added that are used at various stages of the drag and drop operation:

Events that occur with the drag object:

ondragstart (triggered at the beginning of an item drag operation).
ondrag (triggered when an item is dragged).
ondragend (triggered when the user has finished dragging and dropping the item).

Events that occur with the object being dragged onto:

ondragenter (when the item will be transferred to the specified zone (target for transfer)).
ondragover (triggered when an element is moved over a valid transfer zone).
ondragleave (triggered when an element leaves an acceptable zone for transfer).
ondrop (triggered after the dragged item descends on the drag object).

Syntax

<element ondragend="script">

Values

scriptThe name of the script to use when the event has been triggered.

Example

Consider an example in which the <p> element can be moved between two <div> blocks. To do this, we will set four event attributes on the <div> blocks and three on the moveable <p> paragraph.

When we start moving the <p> element, two events are triggered: the first is triggered at the beginning of the operation of dragging the element with the mouse (ondragstart), on which we installed a script that allows you to store data and its type (setData method), the second ondrag event fires at the moment the drag started and informs us of this in the <p id="info"> </p> element.

By default, items cannot be placed in other items. To make this accessible (canceling the default browser) we use the preventDefault() method, which is triggered when an element is moved over a valid zone for transfer (the ondragover event attribute)

ondragenter event occurs when the element is moved to the specified zone, and a script is triggered that sets the background color to yellow and the dashed border to black. When an element leaves a given zone, the border and background style values are returned to their original form (ondragleave event)

The example uses two more event attributes: the first is ondrop, which is triggered when an element descends onto a drag object, a script is launched that allows you to receive data (getData method) and the second attribute of events is ondragend, which is triggered when the user has finished dragging and dropping the element and runs a script that informs us about the completion of the drag and drop procedure in the <p id="info"> </p> element.

HTML

<!DOCTYPE html> 

  <html> 

  <head>

    <title>Attributes for mouse events.  Drag and drop.</title> 

    <style> 

    .dragndrop {

      width: 200px;

      height: 50px;

      border: 3px solid orange;

      padding: 30px;

      text-align: center;

      background: cornsilk;

      float: left;

      margin-right: 20px;

    }

    </style> 

  </head> 

  <body> 

  <p>Move the HTML &lt;p&gt; element between the two rectangles:</p> 

  <div class="dragndrop" ondragenter="dragEnter(event)" ondragleave="dragLeave(event)" ondrop="drop(event)" ondragover="allowDrop(event)"> 

  <p ondragstart="dragStart(event)" ondrag="dragging(event)" ondragend="dragEnd(event)" draggable="true" id="anyid">Move me!</p> 

  </div> 

  <div class="dragndrop" ondragenter="dragEnter(event)" ondragleave="dragLeave(event)" ondrop="drop(event)" ondragover="allowDrop(event)"> </div> 

  <p id="info"> </p> 

<script>

function dragStart ( event ) { 

  event.dataTransfer.setData( "Text" , event.target.id);  

} 

function dragging ( event ) { 

  document.getElementById("info").innerHTML = "The &lt;p&gt; element is being dragged (ondrag)"; 

} 

function allowDrop ( event ) { 

  event.preventDefault();  

} 

function dragEnter ( event ) { 

  if (event.target.className == "dragndrop") { 

    event.target.style.background = "yellow"; 

    event.target.style.border = "3px dotted black"; 

  } 

} 

function dragLeave ( event ) { 

  if (event.target.className == "dragndrop") { 

    event.target.style.background = ""; 

    event.target.style.border = ""; 

  } 

} 

function drop ( event ) { 

  var data = event.dataTransfer.getData ("Text");

  event.target.appendChild(document.getElementById(data));

} 

function dragEnd ( event ) { 

  document.getElementById("info").innerHTML="Draggable &lt;p&gt; element dropped onto the drag object (ondragend)"; 

}

</script> 

  </body> 

</html>