Function Example

pkg/events/events_test.go:109–158

()

}

func Example() {
	// The context typically comes from the request or something.
	ctx := test.Context()

	// This is required for unit test to pass.
	defer test.SetDefaultEventsPubSub(basic.NewPubSub())() //nolint:revive

	// The WaitGroup is only for synchronizing the unit test
	var wg sync.WaitGroup
	wg.Add(1)

	if err := events.Subscribe(ctx, []string{"ns.mac.adr.send_req"}, nil, events.HandlerFunc(func(e events.Event) {
		fmt.Printf("Received event %s\n", e.Name())

		wg.Done() // only for synchronizing the unit test
	})); err != nil {
		panic(err)
	}

	// You can send any arbitrary event; you don't have to pass any identifiers or data.
	events.Publish(events.New(test.Context(), "test.hello_world", "the events system says hello, world"))

	// Defining the event is not mandatory, but will be needed in order to translate the descriptions.
	// Event names are lowercase snake_case and can be dot-separated as component.subsystem.subsystem.event
	// Event descriptions are short descriptions of what the event means.
	// Visibility rights are optional. If no rights are supplied, then the _ALL right is assumed.
	adrSendEvent := events.Define(
		"ns.mac.adr.send_req", "send ADR request",
		events.WithVisibility(ttnpb.Right_RIGHT_APPLICATION_TRAFFIC_READ),
	)

	// These variables come from the request or you got them from the db or something.
	var (
		dev      ttnpb.EndDevice
		requests []ttnpb.MACCommand_LinkADRReq
	)

	// It's nice to be able to correlate events; we use a Correlation ID for that.
	// In most cases, there will already be a correlation ID in the context;
	// this function will append a new one to the ones already in the context.
	ctx = events.ContextWithCorrelationID(ctx, events.NewCorrelationID())

	// Publishing an event to the events package will dispatch it on the "global" event pubsub.
	events.Publish(adrSendEvent.NewWithIdentifiersAndData(ctx, dev.Ids, requests))

	wg.Wait() // only for synchronizing the unit test

	// Output:
	// Received event ns.mac.adr.send_req
}