The EventSource() constructor returns a newly-created EventSource, which represents a remote resource.
Syntax
eventSource = new EventSource(url, configuration);
Parameters
url- A
USVStringthat represents the location of the remote resource serving the events/messages. configurationOptional- Provides options to configure the new connection. The possible entries are:
withCredentials, defaulting tofalse, indicating if CORS should be set toincludecredentials.
Examples
var evtSource = new EventSource('sse.php');
var eventList = document.querySelector('ul');
evtSource.onmessage = function(e) {
var 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 | Status | Comment |
|---|---|---|
| HTML Living Standard The definition of 'EventSource()' in that specification. |
Living Standard | Initial definition |
Browser compatibility
The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.
| Desktop | Mobile | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
EventSource() constructor | Chrome Full support 9 | Edge Full support 79 | Firefox Full support 6 | IE No support No | Opera Full support 11 | Safari Full support 5 | WebView Android Full support Yes | Chrome Android Full support 18 | Firefox Android Full support 45 | Opera Android Full support 12 | Safari iOS Full support 5 | Samsung Internet Android Full support 1.0 |
CORS support (withCredentials) | Chrome Full support 26 | Edge Full support 79 | Firefox Full support 11 | IE No support No | Opera Full support 12 | Safari ? | WebView Android Full support Yes | Chrome Android Full support 26 | Firefox Android Full support 45 | Opera Android Full support 12 | Safari iOS ? | Samsung Internet Android Full support 2.0 |
Legend
- Full support
- Full support
- No support
- No support
- Compatibility unknown
- Compatibility unknown
