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 |
|---|---|---|
| WHATWG HTML Living Standard The definition of 'EventSource()' in that specification. |
Living Standard | Initial definition |
Browser compatibility
| Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari |
|---|---|---|---|---|---|
| Basic support | 9 | 6.0 (6.0) | ? | 11 | 5 |
CORS support (withCredentials) |
26 | 11.0 (11.0) | ? | 12 | ? |
| Available in shared and dedicated workers[1] | (Yes) | 53.0 (53.0) | ? | (Yes) | ? |
| Feature | Android | Firefox Mobile (Gecko) | IE Mobile | Opera Mobile | Safari Mobile |
|---|---|---|---|---|---|
| Basic support | 4.4 | 6.0 (6.0) | ? | ? | ? |
CORS support (withCredentials) |
? | 11.0 (11.0) | ? | ? | ? |
| Available in shared and dedicated workers[1] | ? | 53.0 (53.0) | ? | ? | ? |
[1] But not service workers as yet.