Dragging data into an HTML element

The default behavior only allows text to be dragged into editable regions of the page. You can specify that an element and its children can be made editable by including the contenteditable attribute in the opening tag of the element. You can also make an entire document editable by setting the document object designMode property to "on".

You can support alternate drag-in behavior on a page by handling the dragenter, dragover, and drop events for any elements that can accept dragged data.

Enabling drag-in

To handle the drag-in gesture, you must first cancel the default behavior. Listen for the dragenter and dragover events on any HTML elements you want to use as drop targets. In the handlers for these events, call the preventDefault() method of the dispatched event object. Canceling the default behavior allows non-editable regions to receive a drop.

Getting the dropped data

You can access the dropped data in the handler for the ondrop event:

function doDrop(event){
    droppedText = event.dataTransfer.getData("text/plain");
}

Use the dataTransfer.getData() method to read the data onto the clipboard, passing in the MIME type of the data format to read. You can find out which data formats are available using the types property of the dataTransfer object. The types array contains the MIME type string of each available format.

When you cancel the default behavior in the dragenter or dragover events, you are responsible for inserting any dropped data into its proper place in the document. No API exists to convert a mouse position into an insertion point within an element. This limitation can make it difficult to implement insertion-type drag gestures.