Classgatewayv0.1.0-next.3

EventHandler

Base class for a Discord client event handler.

Pass the event name(s) as the generic, the same one(s) as @RegisterEvent@RegisterEvent. A single-event handler reads this.eventthis.event (the payload tuple) directly. A handler registered for several events branches with this.matchthis.match, keyed by event name, since the union of payload tuples is not directly readable.

abstract class EventHandler<
    Names extends ValidNonInteractionKeys
> extends BaseHandler<ClientEvents[Names]>

abstract class EventHandler<
    Names extends ValidNonInteractionKeys
> extends BaseHandler<ClientEvents[Names]>

\@RegisterEvent([Events.MessageCreate], [Events.MessageUpdate])
class PingPong extends EventHandler<Events.MessageCreate | Events.MessageUpdate> {
    async execute() {
        await this.match({
            [Events.MessageCreate]: (message) => message.reply('pong'),
            [Events.MessageUpdate]: (_oldMessage, edited) => edited.reply('pong')
        });
    }
}

\@RegisterEvent([Events.MessageCreate], [Events.MessageUpdate])
class PingPong extends EventHandler<Events.MessageCreate | Events.MessageUpdate> {
    async execute() {
        await this.match({
            [Events.MessageCreate]: (message) => message.reply('pong'),
            [Events.MessageUpdate]: (_oldMessage, edited) => edited.reply('pong')
        });
    }
}

Member visibility

Filter class members by access level.

constructor

Constructs a new instance of the EventHandlerEventHandler class

EventHandler(
    event: ClientEvents[Names],
    core: Core,
    eventName?: Names
)

EventHandler(
    event: ClientEvents[Names],
    core: Core,
    eventName?: Names
)

Showing members with Protected visibility and higher.

Properties

event

Methods

match()

Names

One or more ClientEventsClientEvents keys, e.g. Events.MessageCreateEvents.MessageCreate or Events.MessageCreate | Events.MessageUpdateEvents.MessageCreate | Events.MessageUpdate.

Names extends ValidNonInteractionKeys

Names extends ValidNonInteractionKeys

event

protected readonly event: SingleEventPayload<Names>

protected readonly event: SingleEventPayload<Names>

match()

Run the arm for whichever event fired. Use this only when the handler is registered for several events. A single-event handler reads this.eventthis.event directly. On a multi-event handler this.eventthis.event is nevernever, so match is the only way to read the payload.

Provide one arm per registered event, keyed by its name, and each arm receives that event's own payload tuple. The arms must cover every event in the generic, a missing event or an unknown key is a compile error.

protected async match<Ret>(
    arms: EventMatchArms<Names, Ret>
): Promise<Ret>

protected async match<Ret>(
    arms: EventMatchArms<Names, Ret>
): Promise<Ret>

Parameter: arms

One handler per registered event, keyed by event name.

\@RegisterEvent([Events.MessageCreate], [Events.MessageUpdate])
class MessageWatcher extends EventHandler<Events.MessageCreate | Events.MessageUpdate> {
    async execute() {
        await this.match({
            [Events.MessageCreate]: (message) => this.scan(message),
            [Events.MessageUpdate]: (_old, updated) => this.scan(updated)
        });
    }
}

\@RegisterEvent([Events.MessageCreate], [Events.MessageUpdate])
class MessageWatcher extends EventHandler<Events.MessageCreate | Events.MessageUpdate> {
    async execute() {
        await this.match({
            [Events.MessageCreate]: (message) => this.scan(message),
            [Events.MessageUpdate]: (_old, updated) => this.scan(updated)
        });
    }
}