express

express.js

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

app.get('', (req, res)=>{       // get or post method
    res.send('Hello, Sunday School -- home page')
})
app.get('/about', (req, res)=>{
    res.send('Hello, Sunday School -- about page')
})
app.listen(8080)
============================================================================
// add html data
app.get('/about', (req, res)=>{
     res.send(`
        <a href='/about'>About</a>
        <h2>Hello, Sunday School -- about page<h2>
        <input type='text' placeholder="Name" value="${req.query.name}">        // localhost:8080/about?name=Sunday
    `)
})

//show json data in object
app.get('/contact', (req, res)=>{
    res.send({
        name: 'Sunday School',
        email: 'contact@sundayschool.co.in'
    })
})

//show json data in array object
app.get('/contact', (req, res)=>{
    res.send([
        {
            name: 'Sunday School',
            email: 'contact@sundayschool.co.in'
        },
        {
            name: 'Sunday School',
            email: 'contact@sundayschool.co.in'
        },
     ])
})

    
// Make a simple html website /////////////////////////////////////////////////////////////////////////////////////////////
// create about.html page > crate public folder and add about.html (or may create multiple pages)
const express = require('express')
const path = require('path')  // help to access the folder
const app = express()

const publicPath = path.join(__dirname, 'public')
app.use(express.static(publicPath)) // use is express js function, staic - load static page

app.listen(5000)

//remove extension from page or redirect the page, create 404 page
const express = require('express')
const path = require('path')  // help to access the folder
const app = express()

const publicPath = path.join(__dirname, 'public')

app.get('',(req, res) =>{
    res.sendFile(`${publicPath}/index.html`)
})

app.get('/aboutus',(req, res) =>{
    res.sendFile(`${publicPath}/about.html`)
})

app.get('*',(req, res) =>{
    res.sendFile(`${publicPath}/404.html`)          // 404 page (page not found)
})

app.listen(5000)

// template engine - EJS -Embedded JavaScript templates (for createing dynamic pages) ------------------------------

//install - https://www.npmjs.com/package/ejs


app.set('view engine', 'ejs')
app.get('/profile', (req, res) =>{
    const user = {
        name: "Preeti",
        skills: ['html', 'javascript']
    }
    res.render('profile', {user})
})

//folder - views - profile.ejs page
<h1>Hi <%= user.name %>, Welcome to Instagram</h1>

<% user.skills.forEach((item) => { %>
    <%= item %>
<%}) %>

// common file--------------------------------------------
//views/common - header.ejs
 <nav>This is header and Nav</nav>   

//views - profile.ejx
<%- include('common/header') %>  
     
//index.html
app.get('/header', (req, res) => {
     res.render('header');
})
                                  
                                  
                                  
// middleware --------------------------------------------------------------------------
var express = require('express');
var app = express();

const reqFilter = (req, res, next) => {
    if(!req.query.age){
        res.send('Please provide your age')
    }else if(req.query.age < 18){
        res.send('You can not access this website')
    }else{
        next()
    }
}

//check resule http://localhost:8080/?age=5

app.use(reqFilter)
app.get('/', (req, res)=> {
    res.send('welcome to homepage')
});

app.get('/about', (req, res)=> {
    res.send('welcome to about page')
});

app.listen(8080);