The HTML Drag and Drop API enables an element to be dragged and dropped.
Drag and Drop
Drag and drop is a very common feature. It is when you "grab" an object and drag it to a different location.
Browser Support
The numbers in the table specify the first browser version that fully supports Drag and Drop.
| API | |||||
|---|---|---|---|---|---|
| Drag and Drop | 4.0 | 9.0 | 3.5 | 6.0 | 12.0 |
HTML Drag and Drop API Example
The example below is a simple drag and drop example:
Example
<!DOCTYPE HTML>
<html>
<head>
<script>
function dragstartHandler(ev) {
ev.dataTransfer.setData("text",
ev.target.id);
}
function dragoverHandler(ev) {
ev.preventDefault();
}
function dropHandler(ev) {
ev.preventDefault();
const data = ev.dataTransfer.getData("text");
ev.target.appendChild(document.getElementById(data));
}
</script>
</head>
<body>
<div id="div1" ondrop="dropHandler(event)"
ondragover="dragoverHandler(event)"></div>
<img id="img1" src="img_logo.gif"
draggable="true" ondragstart="dragstartHandler(event)" width="336"
height="69">
</body>
</html>Live preview
It might seem complicated, but lets go through all the different parts of a drag and drop event.
Make an Element Draggable
First of all: To make an element draggable, set the draggable attribute to true:
<img id="img1" draggable="true">or:
<p
id="p1" draggable="true">Draggable text</p>What to Drag - ondragstart and setData()
Then, specify what should happen when the element is dragged.
In the example above, the ondragstart attribute of the <img> element calls a function (dragstartHandler(ev)), that specifies what data to be dragged.
The dataTransfer.setData() method sets the data type and the value of the dragged data:
function dragstartHandler(ev) {
ev.dataTransfer.setData("text",
ev.target.id);
}In this case, the data type is "text" and the value is the id of the draggable element ("img1").
Where to Drop - ondragover
The ondragover attrribute of the <div> element calls a function (dragoverHandler(ev)), that specifies where the dragged data can be dropped.
By default, data/elements cannot be dropped in other elements. To allow a drop, we must prevent the default handling of the element.
This is done by calling the preventDefault() method for the ondragover event:
function dragoverHandler(ev) {
ev.preventDefault();
}Do the Drop - ondrop
When the dragged data is dropped, a drop event occurs.
In the example above, the ondrop attribute of the <div> element calls a function, dropHandler(event):
function dropHandler(ev) {
ev.preventDefault();
const
data = ev.dataTransfer.getData("text");
ev.target.appendChild(document.getElementById(data));
}Code explained
- Call preventDefault() to prevent the browser default handling of the data (default is open as link on drop)
- Get the dragged data with the dataTransfer.getData() method. This method will return any data that was set to the same type in the setData() method
- The dragged data is the id of the dragged element ("img1")
- Append the dragged element into the drop element
Example
How to drag and drop an image back and forth between two <div> elements: