Mittwoch, 18. Mai, 2016

Delving into Node.js and Express web framework 37
Controller
Now, in the app/controllers folder, create a file named index.server.controller.js with the
following lines of code:
1 exports.render = function(req, res) {
2 res.send('Howdy World');
3 };
Here we’re using a CommonJS module pattern to define a function named render() which we’ll
then later use to require this module and use its function.
Express routing
Once we’ve created a controller, we’ll need to use Express routing functionality to make use of this
controller. Express routing example is shown in the following code snippet:
1 app.get('/', function(req, res) {
2 res.send('This is a GET request');
3 });
This tells Express to execute the middleware function for any HTTP request that comes through a
GET method and is directed to the root path (‘/’). If we would need to deal with POST requests, we
would simply use app.post.
Express can chain several middlewares in a single routing definition, which means that middleware
functions will be called in order. This is usually used to validate requests before executing the
response logic. To understand this better, lets take a look at the following example:
1 var port = 1337;
2 var express = require('express');
3
4 var nameExists = function(req, res, next) {
5 if (req.param('name')) {
6 next();
7 }
8 else {
9 res.send('What is your name?');
10 }
11 };
12
13 var sayHowdy = function(req, res, next) {