Message Package

Package provides a simple message broker implementation.

The message broker is a Pub/Sub one. It implements two different interfaces, Publisher and Subscriber, which are also defined within this package.

Published messages contain the topic where they are published and optional message data. Subscribing to the TopicAll topic triggers the callback for messages published to any topic.

Repository can be found at jeronimoalbi/gnome, as part of jeronimoalbi's Gno smart contracts monorepo.

Usage

 1package main
 2
 3import "gno.land/p/jeronimoalbi/message"
 4
 5func main() {
 6	broker := message.NewBroker()
 7
 8	// Subscribe to an event
 9	subID, err := broker.Subscribe("EventName", func(msg message.Message) {
10		println("EventName has been triggered:", msg.Data.(string))
11	})
12	if err != nil {
13		panic(err)
14	}
15
16	// Publish an event
17	err = broker.Publish("EventName", "Example event data")
18	if err != nil {
19		panic(err)
20	}
21
22	// Unsubscribe from the event
23	unsubscribed, err := broker.Unsubscribe("EventName", subID)
24	if err != nil {
25		panic(err)
26	}
27
28	if !unsubscribed {
29		panic("subscription not found")
30	}
31
32	// Nothing is triggered after unsubscribing
33	err = broker.Publish("EventName", "Ignored event data")
34	if err != nil {
35		panic(err)
36	}
37}
38
39// Output:
40// EventName has been triggered: Example event data