Implement Routing and CRUD

In this chapter, we will build the routing for the API.

Step 1: Create TS file for routing

Remember in part 1 of this project. We save everything in lib folder. So I will create routes folder with a file named crmRoutes.ts that will save all the routes for this project.

// /lib/routes/crmRoutes.ts

import {Request, Response} from "express";

export class Routes {
    public routes(app): void {
        app.route('/')
        .get((req: Request, res: Response) => {
            res.status(200).send({
                message: 'GET request successfulll!!!!'
            })
        })
    }
}

After creating our first route, we need to import it to the lib/app.ts.

// /lib/app.ts

import * as express from "express";
import * as bodyParser from "body-parser";
import { Routes } from "./routes/crmRoutes";

class App {

    public app: express.Application;
    public routePrv: Routes = new Routes();

    constructor() {
        this.app = express();
        this.config();
        this.routePrv.routes(this.app);
    }

    private config(): void{
        this.app.use(bodyParser.json());
        this.app.use(bodyParser.urlencoded({ extended: false }));
    }
}

Now, you can send GET request to your application (http://localhost:3000) directly or by using Postman .

Step 2: Building CRUD for the Web APIs

I assume that you have a basic understanding of HTTP request (GET, POST, PUT and DELETE). If you don’t, it is very simple:

• GET: for retrieving data
• POST: for creating new data
• PUT: for updating data
• DELETE: for deleting data

Now we will build the routing for building a contact CRM that saves, retrieves, updates and deletes contact info.

// /lib/routes/crmRoutes.ts

import {Request, Response} from "express";

export class Routes {

    public routes(app): void {

        app.route('/')
        .get((req: Request, res: Response) => {
            res.status(200).send({
                message: 'GET request successfulll!!!!'
            })
        })

        // Contact
        app.route('/contact')
        // GET endpoint
        .get((req: Request, res: Response) => {
        // Get all contacts
            res.status(200).send({
                message: 'GET request successfulll!!!!'
            })
        })
        // POST endpoint
        .post((req: Request, res: Response) => {
        // Create new contact
            res.status(200).send({
                message: 'POST request successfulll!!!!'
            })
        })

        // Contact detail
        app.route('/contact/:contactId')
        // get specific contact
        .get((req: Request, res: Response) => {
        // Get a single contact detail
            res.status(200).send({
                message: 'GET request successfulll!!!!'
            })
        })
        .put((req: Request, res: Response) => {
        // Update a contact
            res.status(200).send({
                message: 'PUT request successfulll!!!!'
            })
        })
        .delete((req: Request, res: Response) => {
        // Delete a contact
            res.status(200).send({
                message: 'DELETE request successfulll!!!!'
            })
        })
    }
}

Now the routes are ready for getting HTTP request