EventSource: open event
The open event of the EventSource API is fired when a connection with an event source is opened.
This event is not cancelable and does not bubble.
Syntax
Use the event name in methods like addEventListener(), or set an event handler property.
js
addEventListener("open", (event) => {});
onopen = (event) => {};
Event type
A generic Event.
Examples
js
const evtSource = new EventSource("sse.php");
// addEventListener version
evtSource.addEventListener("open", (e) => {
console.log("The connection has been established.");
});
// onopen version
evtSource.onopen = (e) => {
console.log("The connection has been established.");
};
Specifications
| Specification |
|---|
| HTML Standard # event-open |
| HTML Standard # handler-eventsource-onopen |
Browser compatibility
| desktop | mobile | server | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
open event | ||||||||||||