The onopen property of the EventSource interface is an EventHandler called when an open event is received, that is when the connection was just opened.
Syntax
eventSource.onopen = function
Examples
evtSource.onopen = function() {
console.log("Connection to server opened.");
};
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 'onopen' in that specification. |
Living Standard | Initial definition |
Browser compatibility
| Feature | Chrome | Edge | Firefox (Gecko) | Internet Explorer | Opera | Safari |
|---|---|---|---|---|---|---|
| EventSource support | 6 | No support | 6.0 (6.0) | No support | (Yes) | 5 |
| Available in shared and dedicated workers[1] | (Yes) | No support | 53.0 (53.0) | No support | (Yes) | (Yes) |
| Feature | Android | Firefox Mobile (Gecko) | IE Mobile | Opera Mobile | Safari Mobile |
|---|---|---|---|---|---|
| EventSource support | 4.4 | 45 | No support | 12 | 4.1 |
| Available in shared and dedicated workers[1] | (Yes) | 53.0 (53.0) | No support | (Yes) | (Yes) |
[1] But not service workers as yet.
See also
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