middlewares in express

README.md

@@ -25,3 +25,9 @@ A very simple Web API, using JSON data from a file. We have divided the process
 - In this part, We have implemented basic routing using Express.js .
 
 - To Learn more about how to implement Routing in Node using Express.js, you may refer this <a href="https://iq.opengenus.org/p/20e3950d-43f5-45ce-b2f6-2167c63a601b/"> article</a>.
+
+## 🚀 <a href="https://github.com/OpenGenus/web_api_nodejs/tree/master/part_5_express_middleware">Part 5</a>
+
+- In this part, We have included middlewares in our Express app.
+
+- To Learn more about middlewares in Express.js, you may refer this <a href="https://iq.opengenus.org/p/d1f54e16-0990-4eac-aebd-b60f92055dc4/"> article</a>.

part_5_express_middlewares/README.md

@@ -0,0 +1,44 @@
+# web_api_nodejs
+
+# Part 5: Middlewares in Express.js
+
+## ⭐ What is a Middleware ?
+
+Middlewares are functions that are executed in between i.e in the middle of receiving a request and sending back a response. They are used to manipulate request or response object or to execute any other code.
+
+Middleware functions can perform the following tasks:
+
+- Execute any code.
+- Make changes to the request and the response objects.
+- End the request-response cycle.
+- Call the next middleware function in the stack.
+
+In this part, we have included some middlewares in our Express app.
+
+To understand more about creating the web server, you may refer <a href="https://github.com/OpenGenus/web_api_nodejs/tree/master/part_1">part 1</a>.
+
+To understand more about implementation of Routes in Node, you may refer <a href="https://github.com/OpenGenus/web_api_nodejs/tree/master/part_2">part 2</a>.
+
+To understand more about creating a Web Api in Node, you may refer <a href="https://github.com/OpenGenus/web_api_nodejs/tree/master/part_3">part 3</a>.
+
+To understand more about implementing routing in Express.js , you may refer <a href="https://github.com/OpenGenus/web_api_nodejs/tree/master/part_4_express">part 4</a>.
+
+## 🚀 Get Started
+
+1. Clone or download the repository.
+
+2. Once you've downloaded the repo, Open it in an editor of your choice.
+
+3. Open the terminal and traverse to **part_5_express_middleware** directory.
+
+4. Now run command `npm install` to install all the required dependencies.
+
+5. Now run command `node app.js` to start the server.
+
+6. Open Postman and go to `127.0.0.1:3000` to see your server running.
+
+7. Go to `GET 127.0.0.1:3000`, `POST 127.0.0.1:3000/data`, `GET 127.0.0.1:3000/some-random-route` to test the working of the middlewares.
+
+## 📝 Learn More
+
+To Learn more about how to include middlewares in Express.js, you may refer this <a href="https://iq.opengenus.org/p/d1f54e16-0990-4eac-aebd-b60f92055dc4/"> article</a>.

part_5_express_middlewares/app.js

@@ -0,0 +1,39 @@
+// Require express
+
+const express = require("express");
+const app = express();
+const morgan = require("morgan");
+
+app.use(express.json());
+app.use(morgan("dev"));
+
+// Middleware
+app.use((req, res, next) => {
+  console.log("Hello from the middleware !");
+  next();
+});
+
+// Listening to server
+const port = 3000;
+app.listen(3000, () => {
+  console.log(`App running on port ${port}`);
+});
+
+// Routes
+
+app.get("/", (req, res) =>
+  res
+    .status(200)
+    .json({ message: "Hello from the server !", app: "Express-Routes" })
+);
+
+// Middleware
+app.use((req, res, next) => {
+  console.log("Hello from the middleware defined after the route !");
+  next();
+});
+
+app.post("/data", (req, res) => {
+  console.log(req.body);
+  res.status(200).json({ status: "Success !", data: { body: req.body } });
+});