BroadcastChannel.onmessage

The BroadcastChannel.onmessage event handler is a property that specifies the function to execute when a message event, of type MessageEvent, is received by this BroadcastChannel. Such an event is sent by the browser with a message broadcasted to the channel.

Note:

This feature is available in Web Workers.

Syntax

channel.onmessage = function;

Values

  • function is the name of a user-defined function, without the () suffix or any parameters, or an anonymous function declaration, such as function(event) {...}. An event handler always has one single parameter, containing the event, here of type MessageEvent.

Example

bc.onmessage = function(ev) { console.log(`message event received! '${ev.data}'`); };

Specifications

Specification Status Comment
HTML Living Standard
The definition of 'BroadcastChannel.onmessage' in that specification.
Living Standard Initial definition.

Browser compatibility

BCD tables only load in the browser

See also

  • Another, more heavy weight, way of communicating between browser contexts: ServiceWorker