HTMLElement: dragstart event
Baseline Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.
The dragstart
event is fired when the user starts dragging an element or text selection.
This event is cancelable and may bubble up to the Document
and Window
objects.
Syntax
Use the event name in methods like addEventListener()
, or set an event handler property.
addEventListener("dragstart", (event) => {});
ondragstart = (event) => {};
Event type
Event properties
In addition to the properties listed below, properties from the parent interface, Event
, are available.
DragEvent.dataTransfer
Read only-
The data that is transferred during a drag-and-drop interaction.
Examples
Setting opacity on drag start
In this example, we have a draggable element inside a container. Try grabbing the element, dragging it, and then releasing it.
We listen for the dragstart
event to make the element half transparent while dragged.
For a complete example of drag and drop, see the page for the drag
event.
HTML
<div id="container">
<div id="draggable" draggable="true">This div is draggable</div>
</div>
<div class="dropzone"></div>
CSS
body {
/* Prevent the user from selecting text in the example */
user-select: none;
}
#draggable {
text-align: center;
background: white;
}
#container {
width: 200px;
height: 20px;
background: blueviolet;
padding: 10px;
}
.dragging {
opacity: 0.5;
}
JavaScript
const source = document.getElementById("draggable");
source.addEventListener("dragstart", (event) => {
// make it half transparent
event.target.classList.add("dragging");
});
source.addEventListener("dragend", (event) => {
// reset the transparency
event.target.classList.remove("dragging");
});
Result
Specifications
Specification |
---|
HTML Standard # ix-handler-ondragstart |
HTML Standard # event-dnd-dragstart |
Browser compatibility
BCD tables only load in the browser