WebSocket: close event
Baseline
Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.
Note: This feature is available in Web Workers.
The close event is fired when a connection with a WebSocket is closed.
Syntax
Use the event name in addEventListener():
addEventListener("close", (event) => { })
Alternatively, assign to the event handler property of the interface:
onclose = (event) => { }
Event type
A CloseEvent. Inherits from Event.
Examples
You might want to know when the connection has been closed so that you can update the UI or, perhaps, save data about the closed connection. Given that you have a variable called exampleSocket that refers to an opened WebSocket, this handler would handle the situation where the socket has been closed.
exampleSocket.addEventListener("close", (event) => {
console.log("The connection has been closed successfully.");
});
You can perform the same actions using the event handler property, like this (but note that this replaces other event listeners added using onclose, if any):
exampleSocket.onclose = (event) => {
console.log("The connection has been closed successfully.");
};
Specifications
| Specification |
|---|
| WebSockets # dom-websocket-onclose |