Templates and Template Engines

• To use templates, you need to set view engine
• Template is the view, in my understanding
• After installation, set the view engine using app.set()

The Code

var express = require('express');
var app = express();

var port = process.env.PORT || 3000;

//the use of middleware to handle static files
app.use('/assets', express.static(__dirname + '/public'));

//use ejs template engine
//set view engine and ejs so node knows where to find these files
//note: by default, express will look for view files in a folder called views
//but you can change that using app.set()
app.set('view engine', 'ejs');

//again, middleware
app.use('/', function (req, res, next) {
    console.log('Request Url:' + req.url);
    next();
});


//below three are routings
app.get('/', function(req, res) {
  //use render, instead of res.send .. you're utilizing the template engine
    //notice here you don't have to munally reponse the a request,
    //you can just use render in express and express will look for views folder and find
    //the file you provided with the ejs extension you just set
    //it's nice that you don't have to set file extension here, by you can change template engine if you want
    res.render('index');
});

app.get('/person/:id', function(req, res) {
    //so the data in the json object will be passed to person.ejs
    //notice you don't need to reference the object
    //you can use the properties in that object directly
    //the value of ID is from the req.params.id that url provided
    //the JSON object that you give the view is generally called model
    //req.params just mean ``person/stanley`` not querystring
    res.render('person', { ID: req.params.id });
});

app.get('/api', function(req, res) {
    res.json({ firstname: 'John', lastname: 'Doe' });
});

app.listen(port);