42 lines
1.8 KiB
TypeScript
42 lines
1.8 KiB
TypeScript
import { EMPTY, Observable, filter } from "rxjs";
|
|
|
|
import { Message, CommandDefinition } from "./types";
|
|
|
|
/**
|
|
* A class that allows for listening to messages coming through the application,
|
|
* allows for listening of all messages or just the messages you care about.
|
|
*
|
|
* @note Consider NOT using messaging at all if you can. State Providers offer an observable stream of
|
|
* data that is persisted. This can serve messages that might have been used to notify of settings changes
|
|
* or vault data changes and those observables should be preferred over messaging.
|
|
*/
|
|
export class MessageListener {
|
|
constructor(private readonly messageStream: Observable<Message<object>>) {}
|
|
|
|
/**
|
|
* A stream of all messages sent through the application. It does not contain type information for the
|
|
* other properties on the messages. You are encouraged to instead subscribe to an individual message
|
|
* through {@link messages$}.
|
|
*/
|
|
allMessages$ = this.messageStream;
|
|
|
|
/**
|
|
* Creates an observable stream filtered to just the command given via the {@link CommandDefinition} and typed
|
|
* to the generic contained in the CommandDefinition. Be careful using this method unless all your messages are being
|
|
* sent through `MessageSender.send`, if that isn't the case you should have lower confidence in the message
|
|
* payload being the expected type.
|
|
*
|
|
* @param commandDefinition The CommandDefinition containing the information about the message type you care about.
|
|
*/
|
|
messages$<T extends object>(commandDefinition: CommandDefinition<T>): Observable<T> {
|
|
return this.allMessages$.pipe(
|
|
filter((msg) => msg?.command === commandDefinition.command),
|
|
) as Observable<T>;
|
|
}
|
|
|
|
/**
|
|
* A helper property for returning a MessageListener that will never emit any messages and will immediately complete.
|
|
*/
|
|
static readonly EMPTY = new MessageListener(EMPTY);
|
|
}
|