DataTransferItemList

The DataTransferItemList object is a list of DataTransferItem objects representing items being dragged. During a drag operation, each DragEvent has a dataTransfer property and that property is a DataTransferItemList.

The individual items can be accessed using the array operator [].

This interface has no constructor.

Properties

DataTransferItemList.length Read only

An unsigned long that is the number of drag items in the list.

Methods

DataTransferItemList.add()

Adds an item (either a File object or a string) to the drag item list and returns a DataTransferItem object for the new item.

DataTransferItemList.remove()

Removes the drag item from the list at the given index.

DataTransferItemList.clear()

Removes all of the drag items from the list.

DataTransferItemList.DataTransferItem()

Getter that returns a DataTransferItem at the given index.

Example

This example shows how to use drag and drop.

JavaScript

function dragstartHandler(ev) {
  console.log("dragStart");

  // Add this element's id to the drag payload so the drop handler will
  // know which element to add to its tree
  const dataList = ev.dataTransfer.items;
  dataList.add(ev.target.id, "text/plain");

  // Add some other items to the drag payload
  dataList.add("<p>Paragraph…</p>", "text/html");
  dataList.add("http://www.example.org","text/uri-list");
}

function dropHandler(ev) {
  console.log("Drop");
  ev.preventDefault();

  // Loop through the dropped items and log their data
  for (const item of ev.dataTransfer.items) {
    if (item.kind === 'string' && item.type.match(/^text\/plain/)) {
      // This item is the target node
      item.getAsString((s) => {
        ev.target.appendChild(document.getElementById(s));
      });
    } else if (item.kind === 'string' && item.type.match(/^text\/html/)) {
      // Drag data item is HTML
      item.getAsString((s) => {
        console.log(`… Drop: HTML = ${s}`);
      });
    } else if (item.kind === 'string' && item.type.match(/^text\/uri-list/)) {
      // Drag data item is URI
      item.getAsString((s) => {
        console.log(`… Drop: URI = ${s}`);
      });
    }
  }
}

function dragoverHandler(ev) {
  console.log("dragOver");
  ev.preventDefault();

  // Set the dropEffect to move
  ev.dataTransfer.dropEffect = "move"
}

function dragendHandler(ev) {
  console.log("dragEnd");
  const dataList = ev.dataTransfer.items;

  // Clear any remaining drag data
  dataList.clear();
}

HTML

<div>
  <p
    id="source"
    ondragstart="dragstartHandler(event);"
    ondragend="dragendHandler(event);"
    draggable="true">
    Select this element, drag it to the Drop Zone and then release the selection
    to move the element.
  </p>
</div>
<div
  id="target"
  ondrop="dropHandler(event);"
  ondragover="dragoverHandler(event);">
  Drop Zone
</div>

CSS

div {
  margin: 0em;
  padding: 2em;
}

#source {
  color: blue;
  border: 1px solid black;
}

#target {
  border: 1px solid black;
}

Result

Specifications

Specification
HTML Standard
# the-datatransferitemlist-interface

Browser compatibility

BCD tables only load in the browser