ondragover Event
Example
Execute a JavaScript when an element is being dragged over a drop target:
<div ondragover="myFunction(event)"></div>
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More "Try it Yourself" examples below.
Definition and Usage
The ondragover event occurs when a draggable element or text selection is being dragged over a valid drop target.
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 event.preventDefault() method for the ondragover event.
Drag and drop is a very common feature in HTML5. It is when you "grab" an object and drag it to a different location. For more information, see our HTML Tutorial on HTML5 Drag and Drop.
Note: To make an element draggable, use the global HTML5 draggable attribute.
Tip: Links and images are draggable by default, and do not need the draggable attribute.
There are many events that are used, and can occur, in the different stages of a drag and drop operation:
- Events fired on the draggable target (the source element):
- ondragstart - occurs when the user starts to drag an element
- ondrag - occurs when an element is being dragged
- ondragend - occurs when the user has finished dragging the element
- Events fired on the drop target:
- ondragenter - occurs when the dragged element enters the drop target
- ondragover - occurs when the dragged element is over the drop target
- ondragleave - occurs when the dragged element leaves the drop target
- ondrop - occurs when the dragged element is dropped on the drop target
Note: While dragging an element, the ondragover event fires every 350 milliseconds.
Browser Support
The numbers in the table specify the first browser version that fully supports the event.
| Event | |||||
|---|---|---|---|---|---|
| ondragover | 4.0 | 9.0 | 3.5 | 6.0 | 12.0 |
Syntax
In JavaScript, using the addEventListener() method:
object.addEventListener("dragover", myScript);
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Note: The addEventListener() method is not supported in Internet Explorer 8 and earlier versions.
Technical Details
| Bubbles: | Yes |
|---|---|
| Cancelable: | Yes |
| Event type: | DragEvent |
| Supported HTML tags: | All HTML elements |
| DOM Version: | Level 3 Events |
More Examples
Example
A demonstration of ALL possible drag and drop events:
<p draggable="true" id="dragtarget">Drag me!</p>
<div
class="droptarget">Drop here!</div>
<script>
/* ----------------- Events fired on the drag target
----------------- */
document.addEventListener("dragstart", function(event) {
// The dataTransfer.setData() method sets the data type and the value of the
dragged data
event.dataTransfer.setData("Text", event.target.id);
// Output some text when starting to drag the p element
document.getElementById("demo").innerHTML = "Started to drag the p
element.";
// Change the opacity of the
draggable element
event.target.style.opacity = "0.4";
});
// While dragging the p element, change the color
of the output text
document.addEventListener("drag", function(event) {
document.getElementById("demo").style.color = "red";
});
// Output
some text when finished dragging the p element and reset the opacity
document.addEventListener("dragend", function(event) {
document.getElementById("demo").innerHTML = "Finished dragging the p
element.";
event.target.style.opacity = "1";
});
/* ----------------- Events fired on the drop target
----------------- */
// When the draggable p element enters the
droptarget, change the DIVS's border style
document.addEventListener("dragenter", function(event) {
if (
event.target.className == "droptarget" ) {
event.target.style.border =
"3px dotted red";
}
});
// By default, data/elements cannot be dropped in
other elements. To allow a drop, we must prevent the default handling of the
element
document.addEventListener("dragover", function(event) {
event.preventDefault();
});
// When the draggable p element leaves
the droptarget, reset the DIVS's border style
document.addEventListener("dragleave", function(event) {
if (
event.target.className == "droptarget" ) {
event.target.style.border = "";
}
});
/* On drop - Prevent the browser default handling of the data
(default is open as link on drop)
Reset the color of the output text and
DIV's border color
Get the dragged data with the
dataTransfer.getData() method
The dragged data is the id of the dragged
element ("drag1")
Append the dragged element into the drop element
*/
document.addEventListener("drop", function(event) {
event.preventDefault();
if ( event.target.className == "droptarget" ) {
document.getElementById("demo").style.color = "";
event.target.style.border = "";
var data =
event.dataTransfer.getData("Text");
event.target.appendChild(document.getElementById(data));
}
});
</script>
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Related Pages
HTML Tutorial: HTML5 Drag and Drop
HTML Reference: HTML draggable Attribute
Event Object
