DataTransferItemList

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 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 bracket notation [].

DataTransferItemList was primarily designed for the HTML Drag and Drop API, and is still specified in the HTML drag-and-drop section, but it is now also used by other APIs, such as ClipboardEvent.clipboardData and InputEvent.dataTransfer. Documentation of DataTransferItemList will primarily discuss its usage in drag-and-drop operations, and you should refer to the other APIs' documentation for usage of DataTransferItemList in those contexts.

This interface has no constructor.

Instance properties

DataTransferItemList.length Read only

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

Instance 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.

Example

This example shows how to use drag and drop.

JavaScript

js
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

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

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

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