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Getting Started

Quick Start in 4 Steps​

Get up and running with typectx in just a few minutes.

1. Installation​

npm install typectx

2. Create a Market​

A market is a namespace where your suppliers are defined. You'll usually create one per application.

import { createMarket } from "typectx"

const market = createMarket()

3. Define Suppliers​

Suppliers create your app's dependencies. Request suppliers hold data from the user's request (request params, cookies, etc.), which cannot be derived from other suppliers, while Product Suppliers are your application's services, components or features. They are factory functions that depend on request data or other products. Factories can return anything: simple values, promises or other functions.

Names given to market.add("") can only contain digits, letters, underscores or $ signs and cannot start with a digit, just like any Javascript identifier. This way, they can be destructured easily to js variables once injected.

// A Request supplier for the user session
const $session = market.add("session").request<{ userId: string }>()

// A Product supplier that depends on the session
const $userService = market.add("userService").product({
    suppliers: [$session],
    // Access the session by destructuring the factory's 1st argument.
    // The property name is the name passed to market.add() during supplier creation.
    factory: ({ session }) => {
        return {
            id: session.userId,
            name: "Jane Doe"
        }
    }
})

4. Assemble at Your Entry Point​

At your application's entry point, assemble your main product, providing any required request data. The index() utility simplifies this process.

import { index } from "typectx"

const session = { userId: "user-123" }

// Assemble the user service with a concrete session
const userService = $userService
    .assemble(index($session.pack(session)))
    .unpack()

console.log(userService.id) // "user-123"

Next Steps​