Propin

A simple and lightweight inversion of control container for TypeScript apps.

About

Propin is a lightweight (2KB) inversion of control (IoC) container for TypeScript apps. Propin has been designed in a way that facilitates its integration with as many libraries and frameworks as possible. Some frameworks/libraries take the control over the creation of instances. For example, React takes control over the creation of instances of a given Component. Propin is an utility that allows you to inject into a property.

Philosophy

Propin has been developed with 2 main goals:

Allow React and other developers to write code that adheres to the SOLID principles.
Add as little runtime overhead as possible.

The Basics

Let’s take a look at the basic usage and APIs of Propin:

Step 1: Declare dependencies using the injector

// file HttpService.ts

class HttpService {
  updateStatus(): void {
    // ...  
  }
}


// file index.ts

import { injector } from 'propin';
import { HttpService } from './HttpService';

injector.bind(HttpService).toInstance(new HttpService());

Step 2: Resolve dependencies using the @inject

// file SomeComponent.tsx

import * as React from 'react';
import { inject } from 'propin';
import { HttpService } from './HttpService';

export class SomeComponent extends React.Component<SomeComponentProps> {
  @inject()
  httpService: HttpService;

  render(): JSX.Element {
    return (
      <div onClick={this.someAction}>
        // ....
      </div>
    );
  }

  someAction = (): void => {
    this.httpService.updateStatus();
  }

License

License under the MIT License (MIT)