BroadcastChannel: postMessage() method

{{APIRef("BroadCastChannel API")}} {{AvailableInWorkers}}

The postMessage() method of the {{domxref("BroadcastChannel")}} interface sends a message, which can be of any kind of {{jsxref("Object")}}, to each listener in any {{glossary("browsing context")}} with the same {{glossary("origin")}}. The message is transmitted as a {{domxref("BroadcastChannel/message_event", "message")}} event targeted at each {{domxref("BroadcastChannel")}} bound to the channel.

Syntax

postMessage(message)

Parameters

• message

  • : Data to be sent to the other window. The data is serialized using the structured clone algorithm. This means you can pass a broad variety of data objects safely to the destination window without having to serialize them yourself.

    [!NOTE] Execution contexts that can message each other may not be in the same agent cluster, and therefore cannot share memory. {{jsxref("SharedArrayBuffer")}} objects, or buffer views backed by one, cannot be posted across agent clusters. Trying to do so will generate a {{domxref("BroadcastChannel/messageerror_event", "messageerror")}} event containing a DataCloneError {{domxref("DOMException")}} on the receiving end.

Return value

None.

Exceptions

• InvalidStateError {{domxref("DOMException")}}
  • : Thrown if the {{domxref("BroadcastChannel")}} has already been closed.
• DataCloneError {{domxref("DOMException")}}
  • : Thrown if any part of the input data is not serializable.

Specifications

{{Specifications}}

Browser compatibility

{{Compat}}

See also

• {{domxref("BroadcastChannel")}}, the interface it belongs to.