@koa/router

What is @koa/router?

@koa/router is a powerful and flexible routing library for Koa, a popular web framework for Node.js. It allows developers to define routes and handle HTTP requests with ease, providing a clean and modular way to build web applications and APIs.

What are @koa/router's main functionalities?

Basic Routing

This code demonstrates how to set up a basic route using @koa/router. It creates a Koa application, defines a router, and sets up a GET route for the root URL that responds with 'Hello World!'.

const Koa = require('koa');
const Router = require('@koa/router');

const app = new Koa();
const router = new Router();

router.get('/', (ctx, next) => {
  ctx.body = 'Hello World!';
});

app.use(router.routes());
app.use(router.allowedMethods());

app.listen(3000);

Route Parameters

This code demonstrates how to use route parameters with @koa/router. It sets up a route that captures a user ID from the URL and responds with the user ID.

const Koa = require('koa');
const Router = require('@koa/router');

const app = new Koa();
const router = new Router();

router.get('/users/:id', (ctx, next) => {
  const userId = ctx.params.id;
  ctx.body = `User ID: ${userId}`;
});

app.use(router.routes());
app.use(router.allowedMethods());

app.listen(3000);

Middleware

This code demonstrates how to use middleware with @koa/router. It defines a logger middleware that logs the HTTP method and URL of each request, and applies it to a route.

const Koa = require('koa');
const Router = require('@koa/router');

const app = new Koa();
const router = new Router();

const logger = async (ctx, next) => {
  console.log(`${ctx.method} ${ctx.url}`);
  await next();
};

router.get('/', logger, (ctx, next) => {
  ctx.body = 'Hello World!';
});

app.use(router.routes());
app.use(router.allowedMethods());

app.listen(3000);

Nested Routes

This code demonstrates how to set up nested routes with @koa/router. It creates a nested router and mounts it under a parent route.

const Koa = require('koa');
const Router = require('@koa/router');

const app = new Koa();
const router = new Router();
const nestedRouter = new Router();

nestedRouter.get('/info', (ctx, next) => {
  ctx.body = 'Nested Route Info';
});

router.use('/nested', nestedRouter.routes(), nestedRouter.allowedMethods());

app.use(router.routes());
app.use(router.allowedMethods());

app.listen(3000);

Other packages similar to @koa/router

koa-router

koa-router is another popular routing library for Koa. It provides similar functionality to @koa/router, including support for route parameters, middleware, and nested routes. However, @koa/router is a more modern and actively maintained fork of koa-router.

express

Express is a widely-used web framework for Node.js that includes built-in routing capabilities. While it is not specifically designed for Koa, it offers similar routing features and is known for its simplicity and flexibility. Developers who prefer a more comprehensive framework might choose Express over Koa and @koa/router.

hapi

Hapi is a rich framework for building applications and services in Node.js. It includes a powerful routing system that supports route parameters, middleware, and nested routes. Hapi is known for its configuration-driven approach and extensive plugin ecosystem, making it a strong alternative to Koa and @koa/router.

README

@koa/router

Router middleware for Koa. Maintained by Forward Email and Lad.

Table of Contents

• Features
• Migrating to 7 / Koa 2
• Install
• Typescript Support
• API Reference
• Contributors
• License

Features

• Express-style routing (app.get, app.put, app.post, etc.)
• Named URL parameters
• Named routes with URL generation
• Match routes with specific host
• Responds to OPTIONS requests with allowed methods
• Support for 405 Method Not Allowed and 501 Not Implemented
• Multiple route middleware
• Multiple and nestable routers
• async/await support

Migrating to 7 / Koa 2

• The API has changed to match the new promise-based middleware signature of koa 2. See the koa 2.x readme for more information.
• Middleware is now always run in the order declared by .use() (or .get(), etc.), which matches Express 4 API.

Install

npm:

npm install @koa/router

Typescript Support

npm install --save-dev @types/koa__router

API Reference

See API Reference for more documentation.

Contributors

Name
Alex Mingoia
@koajs
Imed Jaberi

License

MIT © Alex Mingoia