Write Express Server in Class Based or Object Oriented Way.

Muhammad Semeer — Wed, 13 Apr 2022 13:57:01 +0000

We have seen lot's of examples of express server function based approaches. So I just created a simple express server with OOPs. Checkout

Now We can use express in Class Based Approach

Installation

npm i express-oops

Also make sure that you have Node.js 14 or newer in order to use it.

Create A Server

const { Server } = require('express-oops');

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

const server = new Server(app, 3000);

server.start();

This will start a server on port 3000.

Create A Controller

const { Server, Controller, Methods } = require("express-oops");
const express = require("express");

const server = new Server(express(), 3000);

class IndexController extends Controller {
  path = "";
  routerMiddleWares = [];

  routes = [
    {
      method: Methods.GET,
      path: "/",
      handler: this.index,
    },
  ];

  index(req, res) {
    res.send("Hello World!");
  }
}

server.start(() => console.log("Server started"));
server.loadControllers([new IndexController()]);

Add Middlewares

Global Middlewares
This middleware are invoked on every request.

const { Server, Controller, Methods } = require("express-oops");
const express = require("express");

const server = new Server(express(), 3000);

class IndexController extends Controller {
path = "";
routerMiddleWares = [];

routes = [
    {
    method: Methods.GET,
    path: "/",
    handler: this.index,
    },
];

index(req, res) {
    res.send("Hello World!");
}
}

server.start(() => console.log("Server started"));
server.loadGlobalMiddleWares([
(req, res, next) => {
    console.log("Middleware 1");
    next();
},
]);
server.loadControllers([new IndexController()]);

Controller Level Middleware
This middleware are invoked only on the routes that are defined in the controller.

for example: if we have a Controller with path /user/. We need to use a function in every request that is defined in the controller.

const { Server, Controller, Methods } = require("express-oops");
const express = require("express");

const server = new Server(express(), 3000);

class IndexController extends Controller {
path = "";
routerMiddleWares = [
    [
    (req, res, next) => {
        console.log("Middleware 1");
        next();
    },
    ]
];

routes = [
    {
    method: Methods.GET,
    path: "/",
    handler: this.index,
    },
];

index(req, res) {
    res.send("Hello World!");
}
}

server.start(() => console.log("Server started"));
server.loadControllers([new IndexController()]);

Local Middlewares
Middlewares are defined in the route.