Typesafe Event System - Base Go

main.go

import "events"
import "fmt"

func main() {
  se1 = &someEventListener{}
  se2 = &someEventListener{}
  // Register the Listeners.
  events.SomeEvent.Register(se1)
  events.SomeEvent.Register(se2)
  
  // Trigger the Event.
  events.SomeEvent.Trigger(&someEventPayload{
    message: "Hey, listeners.",
  })
}

// HandleSomeEvent interface implementation.
type someEventListener struct {}
func (el *someEventListener) HandleSomeEvent(payload SomeEventPayload) {
  // Do something with the payload.
  fmt.Println(payload.GetMessage())
}

// SomeEventPayload interface implementation.
type someEventPayload struct {
  message string
}
func (sep *someEventPayload) GetMessage() string {
  return sep.message
}

// SomeEventPayload interface implementation.

some_event.go

// Placed inside the events/.
package events

// This public variable gets initialized on "events" package import.
var SomeEvent someEvent
////////////////////////////////////////////////////////////////////

// Struct with a List of SomeEvent listeners.
type someEvent struct {
	handlers []SomeEventHandler
}

// Example EventPayload Interface.
type SomeEventPayload interface {
  GetMessage() string
}

// Interface, that the SomeEvent listener should implement.
type SomeEventHandler interface {
	HandleSomeEvent(payload SomeEventPayload)
}

// Register a Listener.
func (e *someEvent) Register(handler BackupsUpdatedHandler) {
	e.handlers = append(e.handlers, handler)
}

// Outer packages trigger this function.
func (e *someEvent) Trigger(payload SomeEventPayload) {
	for _, handler := range e.handlers {
		go handler.HandleSomeEvent(payload)
	}
}