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web api event

EventSource: open event

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Available in workers

The open event of the EventSource interface 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.

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.");
};

Specifications

SpecificationsStandards references are available on the canonical MDN page.

Browser compatibility

Browser compatibilityCompatibility data is available on the canonical MDN page.

See also