mitto

mitto provides a simple API around application event handling

Summary

mitto (Latin verb meaning "to send") implements a simple way to manage a set of listeners and dispatch application events to those listeners. mitto is primarily intended for code which sends events to clients, where clients supply one or more listeners.

Table of Contents

• Usage
• Code of Conduct
• Install
• Contributing

Usage

Basic

The easiest way to use mitto is to include it in a type that manages events and listeners:

import github.com/xmidt-org/mitto

type Event {
    // stuff
}

type MyListener interface {
    OnEvent(Event)
}

type MyService struct {
    // could also use mitto.Set if concurrency is
    // managed by MyService or some other means.
    listeners mitto.SyncSet[Event]
}

func (s *MyService) Add(l ...MyListener) {
    mitto.Add(&s.listeners, l...)
}

func (s *MyService) Remove(l ...MyListener) {
    mitto.Remove(&s.listeners, l...)
}

func (s *MyService) DoSomething() {
    // time to send an event:
    s.listeners.Send(Event{
        // stuff
    })
}

AsListener

mitto provides AsListener to convert other common types into listeners.

f := func(event Event) { /* ... */ }
ch := make(chan Event, 10)

s.listeners.Add(
    mitto.AsListener[Event](f),
    mitto.AsListener[Event](ch),
)

Important note on channels

A client is responsible for ensuring that a channel is properly managed to reduce or avoid blocking. In addition, a client must remove the channel listener before closing the channel, otherwise Send may panic.

ch := make(chan Event, 10)
l := AsListener[Event](ch)
s.listeners.Add(l)

// remove the listener BEFORE closing the channel
s.listeners.Remove(l)
close(ch)

Adapting custom Listener interfaces

AsListener can also be used to adapt a different listener interface or type.

type DifferentListener interface {
    OnStartEvent(Event)
}

func (s *MyService) AddDifferentListener(l DifferentListener) {
    s.listeners.Add(
        mitto.AsListener[Event](
            l.OnStartEvent,
        ),
    )
}

Code of Conduct

This project and everyone participating in it are governed by the XMiDT Code Of Conduct. By participating, you agree to this Code.

Install

go get github.com/xmidt-org/mitto@latest

Contributing

Refer to CONTRIBUTING.md.