Sometimes, we want to add REST endpoints with Express.js nested router.

In this article, we’ll look at how to add REST endpoints with Express.js nested router.

How to add REST endpoints with Express.js nested router?

To add REST endpoints with Express.js nested router, we should make sure our route URL and request methods follow the REST convention.

For instance we write

const express = require('express');
const app = express();

const userRouter = express.Router();
const itemRouter = express.Router({
  mergeParams: true
});

userRouter.use('/:userId/items', itemRouter);

userRouter.route('/')
  .get((req, res) => {
    res.status(200)
      .send('hello users');
  });

userRouter.route('/:userId')
  .get((req, res) => {
    res.status(200)
      .send(req.params.userId);
  });

itemRouter.route('/')
  .get((req, res) => {
    res.status(200)
      .send(`items ${req.params.userId}`);
  });

itemRouter.route('/:itemId')
  .get((req, res) => {
    res.status(200)
      .send(`item ${req.params.itemId} user ${req.params.userId}`);
  });

app.use('/user', userRouter);

app.listen(3000);

to nest itemRouter in userRoute.

We have

userRouter.use('/:userId/items', itemRouter);

to nest itemRouter in userRouter.

We set mergeParams to true so that the URL from userRouter is combined with the URLs of the routes with itemRouter.

As a result, we get the following results when the following requests are made:

• GET /user -> hello user
• GET /user/5 -> 5
• GET /user/5/items -> items 5
• GET /user/5/items/6 -> item 6 user 5

Conclusion

To add REST endpoints with Express.js nested router, we should make sure our route URL and request methods follow the REST convention.