SourceBuffer: update event

Available in workers

The update event of the SourceBuffer interface signals the successful completion of an appendBuffer() or remove() operation. The updating attribute transitions from true to false. This event is fired before the updateend event.

Syntax

Use the event name in methods like addEventListener(), or set an event handler property.

addEventListener("update", (event) => { })

onupdate = (event) => { }

Event type

A generic Event.

Examples

Handling the update event after appending data

This example demonstrates how to handle the update event after a successful appendBuffer() operation.

const sourceBuffer = source.addSourceBuffer(mimeCodec);
sourceBuffer.addEventListener("error", () => {
  downloadStatus.textContent = "Error occurred during decoding";
});
sourceBuffer.addEventListener("update", () => {
  downloadStatus.textContent = "Done";
});
sourceBuffer.addEventListener("updateend", () => {
  source.endOfStream();
});
downloadStatus.textContent = "Downloading...";
fetch(assetURL)
  .then((response) => response.arrayBuffer())
  .then((data) => {
    downloadStatus.textContent = "Decoding...";
    sourceBuffer.appendBuffer(data);
  });

Specifications

Browser compatibility

See also

• appendBuffer()
• remove()