breakout-express-router

BREAKOUT - Express Router

The Router

• Express has a built-in router that allows us to store routes in separate files
• We add each route to the router object and pass this object to express as middleware

const express = require('express');
const router = express.Router();

router.get('/:id', (req, res) => {
  // do something
});

router.post('/', (req, res) => {
  // do something
});

Returning the Router

• We can simply return the router object from our router file

// in my-router.js
router.get...

router.post...

module.exports = router;

• We require the exported object into our server file
• We pass the router to app.use along with an argument specifying the prefix for the routes
• If Express receives a request with this prefix, it will pass the request to the router

// in server.js
const myRouter = require('./routes/my-router.js');
app.use('/my-routes', myRouter);

Returning a Function

• We can also export a function that returns our router object
• This allows us to take in a parameter or dependency

// in my-router.js
// export a function that takes in the database connection
module.exports = (db) => {
  router.get...

  router.post...

  return router;
};

• We then have to invoke the function in our server and remember to pass in any dependencies
• This works because the function returns the router object

// in server.js
const dbConnection = require('./db/connection.js');

const myRouterFn = require('./routes/my-router.js');

app.use('/my-routes', myRouterFn(dbConnection));

Useful Links

• Express Router docs

/products => /api/admin/products