The EventSource interface is used to receive server-sent events. It connects to a server over HTTP and receives events in text/event-stream format without closing the connection.
Properties
This interface also inherits properties from its parent, EventTarget.
EventSource.onerror- Is an
EventHandlerbeing called when an error occurs and theerrorevent is dispatched on this object. EventSource.onmessage- Is an
EventHandlerbeing called when amessageevent is received, that is when a message is coming from the source. EventSource.onopen- Is an
EventHandlerbeing called when anopenevent is received, that is when the connection was just opened. EventSource.readyStateRead only- An
unsigned shortrepresenting the state of the connection. Possible values areCONNECTING(0),OPEN(1), orCLOSED(2). EventSource.urlRead only- A
DOMStringrepresenting the URL of the source.
Methods
This interface also inherits methods from its parent, EventTarget.
EventSource.close()- Closes the connection, if any, and sets the
readyStateattribute toCLOSED. If the connection is already closed, the method does nothing.
Specifications
| Specification | Status | Comment |
|---|---|---|
| WHATWG HTML Living Standard The definition of 'EventSource' in that specification. |
Living Standard |
Browser compatibility
| Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari |
|---|---|---|---|---|---|
| Basic support | 9 | 6.0 (6.0) | ? | 11 | 5 |
| CORS support | 26 | 11.0 (11.0) | ? | 12 | ? |
| Feature | Android | Firefox Mobile (Gecko) | IE Mobile | Opera Mobile | Safari Mobile |
|---|---|---|---|---|---|
| Basic support | 4.4 | ? | ? | ? | ? |