SourceBuffer: updatestart event
Limited availability
This feature is not Baseline because it does not work in some of the most widely-used browsers.
Note: This feature is available in Dedicated Web Workers.
The updatestart event of the SourceBuffer interface signals the beginning of an appendBuffer() or remove() operation. The updating attribute transitions from false to true.
Syntax
Use the event name in methods like addEventListener(), or set an event handler property.
js
addEventListener("updatestart", (event) => { })
onupdatestart = (event) => { }
Event type
A generic Event.
Examples
Listening for the updatestart event
js
const sourceBuffer = source.addSourceBuffer(mimeCodec);
sourceBuffer.addEventListener("updatestart", () => {
downloadStatus.textContent = "Modifying buffer...";
});
sourceBuffer.addEventListener("updateend", () => {
downloadStatus.textContent = "Modification complete";
});
Specifications
| Specification |
|---|
| Media Source Extensions™ # dfn-updatestart |
| Media Source Extensions™ # dom-sourcebuffer-onupdatestart |
Browser compatibility
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updatestart event
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Legend
Tip: you can click/tap on a cell for more information.
- Full support
- Full support
- Partial support
- Partial support
- No support
- No support
- Experimental. Expect behavior to change in the future.
- Has more compatibility info.