readme.md

Complete guide for router and controller with debugging

Logic Building :- spilting a big problems into smaller problems and solving them one by one

• some by working on real world projects [80%]
• some by leetcode problems

Let's Start

• Make a new file user.controller.js in the controlller folder of src folder
  • let's code
    • import required methods like asyncHandler
    • write the method
      • this method is doing nothing but sending a ok response with 200 status code

import { asyncHandler } from "../utils/asyncHandler.js";


const registerUser = asyncHandler( async (req , res)=>{

    res.status(200).json(
        {
            message:"ok"
        }
    )
})
export {registerUser}

• Making routes
  • when will this method registerUser will be called , it will be called when a certain url is hit
  • that url route is defined here
  • Go to routes folder and make a file user.routes.js
    • just making a router object and exporting

import { Router } from "express"

const router  = Router()

export default router 

• Go to app.js now and write
  • so import the route and
  • app.use("/api/v1//users" , userRouter) states that when url hit at http://localhost:8000/api/v1/users it will go to userRouter and see the routes in that

//routes import
import  userRouter from './routes/user.routes.js'


// routes declaration
app.use("/users" , userRouter)
export { app }

• now define the routes in the userRoutes
  • import the function to be called
  • now if the client hits the url
    • http://localhost:8000/api/v1/users/register , it will call registerUser function
    • http://localhost:8000/api/v1/users/register , it will call loginUser function
    • so we made a separate file for user as prefix in the url and all other possible

import { Router } from "express"
import { registerUser } from "../controllers/user.controller.js"

const router  = Router()

router.route("/register").post(registerUser)
router.route("/#").post(loginUser)

• Tools to test API

  • thunder client : vscode extension
  • postman : standard api testing tool

• Download Postman and do basic # setup

  • Make a new collection say "backendchai" and a new request
  • send a post req at "http://localhost:8000/api/v1/users/register"
  • output should be
  • { "message": "ok" }