EventSource: readyState property
Baseline Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since January 2020.
Note: This feature is available in Web Workers.
The readyState read-only property of the
EventSource interface returns a number representing the state of the
connection.
Value
A number which is one of the three possible state constants defined on the EventSource interface:
EventSource.CONNECTING(0)-
The connection is not yet open.
EventSource.OPEN(1)-
The connection is open and ready to communicate.
EventSource.CLOSED(2)-
The connection is closed or couldn't be opened.
Examples
js
const evtSource = new EventSource("sse.php");
console.log(evtSource.readyState);
Note: You can find a full example on GitHub — see Simple SSE demo using PHP.
Specifications
| Specification |
|---|
| HTML Standard # dom-eventsource-readystate-dev |
Browser compatibility
BCD tables only load in the browser