EventSource()

The EventSource() constructor returns a newly-created EventSource, which represents a remote resource.

Syntax

new EventSource(url)
new EventSource(url, options)

Parameters

url

A string that represents the location of the remote resource serving the events/messages.

options Optional

Provides options to configure the new connection. The possible entries are:

withCredentials Optional

A boolean value, defaulting to false, indicating if CORS should be set to include credentials.

Examples

const evtSource = new EventSource('sse.php');
const eventList = document.querySelector('ul');

evtSource.onmessage = function(e) {
  const newElement = document.createElement("li");

  newElement.textContent = "message: " + e.data;
  eventList.appendChild(newElement);
}

Note: You can find a full example on GitHub — see Simple SSE demo using PHP.

Specifications

Specification
HTML Standard
# dom-eventsource-dev

Browser compatibility

BCD tables only load in the browser

See also