Syntax

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

addEventListener("open", (event) => { })
onopen = (event) => { }

Event type

A generic Event.

Examples

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.");
};