jeffhall4 / ioc-container

ioc-container

This library provides a very simple IoC container for use in javascript applications. This currently only supports constructor injection into classes.

Getting Started / Installation

Firstly install this package:

$ yarn add ioc-container
$ npm i ioc-container

Create a IocContainer and create your objects:

const container = new IocContainer();
container.create(UserDao); // create an instance of UserDao that has no constructor arguments
const userhttpService = container.create(UserHttpService, UserDao); // create an instance of UserHttpService that uses the avaliable UserDao.

container.registerConst('accountDaoConfig', { url: 'some-url' }); // register a constant under the name 'accountDaoConfig'.
const accountDao = container.create(AccountDao, 'accountDaoConfig'); // create an instance of AccountDao that has one constant constructor argument

Example of simplifying object creation by using chaining:

const container = new IocContainer();
const accountHttpService = container
        .register(UserDao)
        .registerConst('accountDaoConfig', { url: 'some-url' })
        .register(AccountDao, 'accountDaoConfig')
        .create(AccountHttpService, UserDao, AccountDao);

Functionality Roadmap

• Support singleton vs prototype objects
• Auto create objects as needed. (and handle circular dependency check.)
• Support accessor injection
• Support function argument injection
• Support a mode where object construction is delayed so order does not matter.
• Add error codes to exceptions

Known Issues

• The number of constructor args given is not checked against the constructor signature
• create will create a new instance of an object each time but the argument resolution will use the most recently created instance. It should consistently reuse instances.

Developer tooling Roadmap

• Better jsdocs for public functions
• Add better Readme documentation.
• Add a Contributing.md with branching strategy, release process and versioning strategy,
• Publish this to NPM.
• Add CI integration.
• Support windows development (non bash) environments.