'ResponseMessageHandler' Type

The ResponseMessageHandler is a TypeScript utility type that describes the shape of a handler function used with addZpaxMessageListener. It ensures that the handler receives the correct message type and corresponding data.

Definition

export type ZpaxMessage<T, D> = {
  type: T;
  data: D;
};

export type ResponseMessageHandler<T extends keyof ResponseMessage> = (
  data: ZpaxMessage<T, ResponseMessage[T]>
) => void;

Explanation

• ZpaxMessage<T, D> Represents a message object with a type and data field.

• ResponseMessageHandler<T> A function that takes a ZpaxMessage where:

  • T is a key of the ResponseMessage interface, representing a specific message type.

  • data is typed to match the corresponding value in ResponseMessage[T].

Example Usage

addZpaxMessageListener('last_interaction', (message) => {
  const timestamp = message.data;
  console.log('Last interaction time:', timestamp);
});

Here:

'last_interaction' is a key of ResponseMessage.

message.data will be typed as ResponseMessage['last_interaction'].