react

@iniettore/react

React bindings for iniettore

@iniettore/react supports large React applications that makes use of code-splitting techniques to deliver code to their clients.

Install

Using npm:

npm install @iniettore/react --save

Using Yarn:

yarn add @iniettore/react

Usage

We will explain how to use @iniettore/react binding via an example. See below a quite typical Logger interface and a concrete implementation of it (i.e. ConsoleLogger).

Logger.ts

export default interface Logger {
  log(msg: string): void
}

ConsoleLogger.ts

import Logger from './Logger'

class ConsoleLogger implements Logger {
  log(msg: string) {
    console.log(msg)
  }
}

Let's then assume you have a React App component and a component nested quite deep in the App render tree. We will call such component MyNestedComponent.

For the purpose of this example we will assume MyNestedComponent needs to log something very important on its first render.

App.tsx

import React from 'react'

export default function App () {
  return (
    { /* my app components */ }
  )
}

MyNestedComponent.tsx

import React, { useEffect } from 'react'

export default function MyNestedComponent () {
  useEffect(() => {
    // needs to log something
  }, [])

  return (
    /* my component render tree */  
  )
}

One can define an Iniettore Context associated with the App component by using the @iniettore/react <Container /> component.

App.tsx

import React from 'react'
import { Container } from '@iniettore/react'
import { describe } from './modules'

export default function App () {
  return (
    <Container describe={describe}>
      { /* my app components */ }
    </Container>
  )
}

If you already using Iniettore you are probably familiar with the container function from the iniettore package. If not you can check the iniettore documentation here.

The container function accepts a describe callback that is meant to specify the Iniettore Context objects and their relationships.

<Container /> accepts a describe function which is similar to the one used to with the container function in the core library.

modules.ts

import { singleton } from 'iniettore'
import ConsoleLogger from './ConsoleLogger'

export function describe () {
  return {
    logger: singleton(() => new ConsoleLogger())
  }
}

The MyNestedComponent can then access the concrete instance of Logger with the Iniettore useContext React hook.

MyNestedComponent.tsx

import React, { useEffect } from 'react'
import { useContext as useIniettoreContext } from '@iniettore/react'
import Logger from './Logger'

export default function MyNestedComponent () {
  const { logger } = useIniettoreContext<{ logger: Logger }>()

  useEffect(() => {
    logger.log('I made it!')
  }, [])

  return (
    /* my component render tree */  
  )
}

Modular React applications

It's not uncommon for non-trivial React applications to make use of code-splitting and lazy loading techniques in order to optimize the way code is bundled and delivered to clients.

Let's use the example of an application that has been splitted into 3 application sub-modules. See components diagram below.

                          ┌──────────────┐
                       ┌──┴─┐            │
                       └──┬─┘            │
                          │     Main     │
                       ┌──┴─┐            │
                       └──┬─┘            │
                          └───────┬──────┘
                                  │
                                  │
           ┌──────────────────────┼───────────────────────┐
           │                      │                       │
           │                      │                       │
   ┌───────┴──────┐       ┌───────┴──────┐        ┌───────┴──────┐
┌──┴─┐            │    ┌──┴─┐            │     ┌──┴─┐            │
└──┬─┘            │    └──┬─┘            │     └──┬─┘            │
   │  Component A │       │  Component B │        │  Component C │
┌──┴─┐            │    ┌──┴─┐            │     ┌──┴─┐            │
└──┬─┘            │    └──┬─┘            │     └──┬─┘            │
   └──────────────┘       └──────────────┘        └──────────────┘

@iniettore/react makes the job of wiring dependencies across application sub-modules as trivial as rendering a React component.

Let's assume that our hypothetical application has some logging constraints that require to have only one Logger object for the entire application. Such instance must be registered in the main Iniettore Context defined and injected in the App root component.

main/modules.ts

import { singleton } from 'iniettore'
import ConsoleLogger from './ConsoleLogger'

export function describe () {
  return {
    logger: singleton(() => new ConsoleLogger())
  
    /* other bindings */
  }
}

main/App.tsx

import React from 'react'
import { Container } from '@iniettore/react'
import { describe } from './modules'

export default function App () {
  return (
    <Container describe={describe}>
      { /* render logic eventually renders <ComponentA /> */ }
    </Container>
  )
}

Component A can be defined as a React component that uses Iniettore <Container /> to define its own Iniettore Context for its internal wiring needs. The describe function will receive a reference to the Iniettore Context injected by the App component.

component-a/modules.ts

import { Context, singleton } from 'iniettore'
import Logger from '../Logger'
import HeroService from './HeroService'

export function describe (main: Context<{ logger: Logger }>) {
  return {
    hero: singleton(() => new HeroService(get(main.logger)))
  
    /* other bindings */
  }
}

component-a/Root.tsx

import React from 'react'
import { describe } from './modules'

export default function Root () {
  return (
    <Container describe={describe}>
      { /* Component A components */ }
    </Container>  
  )
}

License

ISC