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 methods like addEventListener(), or set an event handler property.
addEventListener("close", (event) => { })
onclose = (event) => { }
Event type
A CloseEvent. Inherits from Event.
Event properties
In addition to the properties listed below, properties from the parent interface, Event, are available.
codeRead only-
Returns an
unsigned shortcontaining the close code sent by the server. reasonRead only-
Returns a string indicating the reason the server closed the connection. This is specific to the particular server and sub-protocol.
wasCleanRead only-
Returns a boolean value that Indicates whether or not the connection was cleanly closed.
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:
exampleSocket.onclose = (event) => {
console.log("The connection has been closed successfully.");
};
Specifications
| Specification |
|---|
| WebSockets # dom-websocket-onclose |
Browser compatibility
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