Write Express Server in Class Based or Object Oriented Way.

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

1. 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()]);
   

2. 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()]);
   

3. Local Middlewares
   Middlewares are defined in the route.
   

   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,
       localMiddleWares: [
           (req, res, next) => {
           console.log("Middleware 1");
           next();
           },
       ],
       },
   ];
   
   index(req, res) {
       res.send("Hello World!");
   }
   }
   
   server.start(() => console.log("Server started"));
   server.loadControllers([new IndexController()]);