Types

BroadcastMessage

interface BroadcastMessage {
  id: string; // unique message identifier
  type: string; // the label passed to postMessage
  message: any; // your payload
  timestamp: number; // creation time (ms)
  source: string; // sourceName of the sending tab
  expirationDate?: number; // set when sent with an expiry
}

SendMessageOptions

interface SendMessageOptions {
  expirationDuration?: number; // ms until the message expires
  expirationDate?: number; // absolute expiry timestamp
}

ClearReceivedMessagesOptions

interface ClearReceivedMessagesOptions {
  ids?: string[]; // clear specific messages
  types?: string[]; // clear by message type
  sources?: string[]; // clear by source name
}

ClearSentMessagesOptions

interface ClearSentMessagesOptions {
  ids?: string[];
  types?: string[];
  sync?: boolean; // also clear other tabs' received copies
}

GetLatestMessageOptions

interface GetLatestMessageOptions {
  type?: string;
  source?: string;
}

MessageCallback and OnMessageMap

type MessageCallback = (msg: BroadcastMessage) => void;
type OnMessageMap = { [type: string]: MessageCallback };

onMessage accepts either a single callback for all incoming messages or a type-keyed map. It fires after the message is added to state and only for messages passing every filter. Internal messages (PING, PONG, CLEAR_SENT_MESSAGES) never trigger it.