DEPRECATION NOTICE: For a better, production-ready compile-time dependency injection library, use https://github.com/google/wire.

drgomesp/cargo

An efficient and robust Go dependency injection container – by Daniel Ribeiro

Table of Contents

1. Introduction
2. Installation
3. Getting Started

Introduction

cargo is a library that provides a powerful way of handling objects and their dependencies, by using the Container. The container works by implementing the Dependency Injection pattern via constructor injection, resulting in explicit dependencies and the achievement of the Inversion of Control principle.

Installation

$ go get github.com/drgomesp/cargo

Getting Started

Creating/Registering Services

There are two main methods used to define services in the container: container.Register and container.Set. The first one assumes you already have a pointer to an object instance to work with, the second needs a definition.

Suppose you have an object:

type HttpClient struct {}

client := new(HttpClient)

To define that as a service, all you need to do is:

dic := container.NewContainer()
dic.Set("http.client", client)

From now on, whenever you need to work with the http client service, you can simply do:

if s, err := dic.Get("http.client"); err != nil {
    panic(err)
}

client := s.(*HttpClient) // the type assertion is required

Or, if you do not need errors handling and panic is fine, you can get the same behavior with short synthax:

client := dic.MustGet("http.client").(*HttpClient)

by Daniel Ribeiro