what and why
server logic is complex ->
ex- parse incoming request
we have to manually listen for data event
end event
create a buffer
convert to string
just to get one type of data.. imagine you want to get a file.. crazy hah?
for easily manage these -> introduced express js
install production dependency
npm install --save express
Adding Middlewares
const express = require("express");
const app = express();
app.use((req, res, next) => { //This is a middleware
console.log("In the Middleware");
res.send("<h1>Hello From Node JS server</h1>");
});
app.listen(3000);
console.log("Server running at http://127.0.0.1:3000/");
- Middleware is used for getting requests sending responses and calling to other middlewares set routings and many more
Explanation ->
//const http = require("http"); //... warning comes unfortunatly es6
is not supported by browsers yet
const express = require("express");
const app = express();
//Middlewares
//used for every incoming request
app.use((req, res, next) => {
console.log("In the 1st Middleware");
next(); //Allows to calls the next middleware (middleware2)
//if we diidnt call it -> request will die
});
app.use((req, res, next) => {
console.log("In the 2nd Middleware");
//res.setHeader() can set headers
res.send("<h1>Hello From Node JS server</h1>"); //allows to send a response
//express set the headers automatically
//we can also set manually by-> res.setHeader()
});
// const ser ver = http.createServer(app);
// server.listen(3000); //also removed import
//both lines in above can be replaced with
app.listen(3000);
console.log("Server running at http://127.0.0.1:3000/");
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