node express docs code example

Example 1: node js express

basic server

const express =require('express');
const app = express();
const PORT = 5000;


app.get('/',(req,res)=>{
   res.json({message: 'Welcome to the backend'})
})


app.listen(PORT ,()=>console.log(`Connected to ${PORT}`)

Example 2: node js express

// node js -> express -> basic example: static folder, 404 page

const express = require('express');
const path = require('path');
const PORT = process.env.PORT || 5000;

const app = express();

function error404(req, res) {
  res.status(404);

  if (req.accepts('html')) {
    res.sendFile(path.join(__dirname, 'public/errors/404.html'));
    return;
  }

  if (req.accepts('json')) {
    res.send({
      status: 404,
      error: 'Not found'
    });
    return;
  }
  
  res.type('txt').send('404 - Not found');
}

app
  .use(express.static(path.join(__dirname, 'public')))
  .use(error404)
  .listen(PORT, () => console.log(`Listening on ${ PORT }`));

Example 3: express render

// send the rendered view to the client
res.render('index')

// if a callback is specified, the rendered HTML string has to be sent explicitly
res.render('index', function (err, html) {
  res.send(html)
})

// pass a local variable to the view
res.render('user', { name: 'Tobi' }, function (err, html) {
  // ...
})