@daisugi/kado

Kado is a minimal and unobtrusive inversion of control container.

Usage no npm install needed!

<script type="module">
  import daisugiKado from 'https://cdn.skypack.dev/@daisugi/kado';
</script>

README

@daisugi/kado

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This project is part of the @daisugi monorepo.

Well tested. | Without any external code dependencies and small size. | Used in production.

Kado is a minimal and unobtrusive inversion of control container.

Usage

import { kado } from '@daisugi/kado';

const { container } = kado();

class Foo {
  constructor(bar) {
    this.bar = bar;
  }
}

class Bar {}

container.register([
  {
    token: 'Foo',
    useClass: Foo,
    params: ['Bar'],
  },
  {
    token: 'Bar',
    useClass: Bar,
  },
]);

const foo = container.resolve('Foo');

Table of contents

Install

Using npm:

npm install @daisugi/kado

Using yarn:

yarn add @daisugi/kado

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Motivation

This library is a result of a series of the requirements that either were not met by other libraries of same type, or were partially met, or finally met everything but also brought an overhead not required by the project.

If you feel that any of the following requirements is close to your demand, feel free to use this library, otherwise there are many other good IoC libraries out there such as di-ninja or tsyringe, among many others that you can use.

  • ✔️ Should allow to create multiple instances of the container, and not share the state globally (useful when multiple packages are using it, or in monorepo).
  • ✔️ The DI configuration must be abstracted from the base code, and must be able to be easily ported (Composition Root).
  • ✔️ Dependencies must be able easily decorated (useful to add telemetry, debug ...).
  • ✔️ Avoid use of decorators by annotations (see style guide).
  • ✔️ Should work with pure JavaScript (don't depend of any superset like TypeScript).
  • ✔️ Keep the API simple (singleton and not, classes, values, factories, and not much more), but with enough pieces to cover the most common use cases.

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API

token

Is the name used to register the dependency, to later be resolved.

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useClass

Can go along with params property, which contains tokens with which the class should be resolved.

Usage

import { kado } from '@daisugi/kado';

const { container } = kado();

class Foo {
  constructor(bar) {
    this.bar = bar;
  }
}

class Bar {}

container.register([
  {
    token: 'Foo',
    useClass: Foo,
    params: ['Bar'],
  },
  {
    token: 'Bar',
    useClass: Bar,
  },
]);

const foo = container.resolve('Foo');

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useValue

Useful for storing constants.

Usage

import { kado } from '@daisugi/kado';

const { container } = kado();

container.register([
  {
    token: 'foo',
    useValue: 'text',
  },
]);

const foo = container.resolve('foo');

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useFactoryWithContainer

Provides container as argument to the factory method.

Usage

import { kado } from '@daisugi/kado';

const { container } = kado();

class Foo {}

function bar(c) {
  return c.resolve('Foo');
}

container.register([
  {
    token: 'Foo',
    useClass: Foo,
  },
  {
    token: 'bar',
    useFactoryWithContainer: bar,
  },
]);

const foo = container.resolve('bar');

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useFactory

Same as useFactoryWithContainer, except provides params to it, instead of the container.

Usage

import { kado } from '@daisugi/kado';

const { container } = kado();

class Foo {}

function bar(foo) {
  return foo;
}

container.register([
  {
    token: 'Foo',
    useClass: Foo,
  },
  {
    token: 'bar',
    useFactory: bar,
    params: ['Foo'],
  },
]);

const foo = container.resolve('bar');

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scope

Scope can be Transient or Singleton, by default it's Singleton. Can be used along with useClass, useFactoryWithContainer and useFactory. Having scope as Transient it will create a new instance every time the dependency is resolved, Singleton will reuse the already created instance.

Usage

import { kado } from '@daisugi/kado';

const { container } = kado();

class Foo {}

container.register([
  {
    token: 'Foo',
    useClass: Foo,
    scope: 'Transient',
  },
]);

const foo = container.resolve('Foo');

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#list()

Get the list of the registered dependencies.

Usage

import { kado } from '@daisugi/kado';

const { container } = kado();

class Foo {}

container.register([
  {
    token: 'Foo',
    useClass: Foo,
    scope: 'Transient',
  },
]);

const manifest = container.list();

// Now you can iterate the manifest items and decorate methods.

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Goal

The project aims to provide the basic functionality for IoC. The functionality will be kept simple and will not be overextended.

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Etymology

Kado is a Japanese art that involves an arrangement of a variety of plants. A characteristic of Japanese Kado is an emphasis on shapes and lines, as well as the manner in which the flower is placed into the dish.

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Other projects

Project Version Changelog Description
Daisugi version changelog Is a minimalist functional middleware engine.
Kintsugi version changelog Is a set of utilities to help build a fault tolerant services.
Oza version changelog Is a fast, opinionated, minimalist web framework for NodeJS.
JavaScript style guide

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License

MIT