Traducción en curso

En este primer articulo de Express resolveremos las preguntas "¿Qué es Node?" y "¿Qué es Express?", y te daremos una visión general de que hace especial al framework web "Express". Delinearemos las características principales, y te mostraremos algunos de los principales bloques de construcción de una aplicación en Express (aunque en este punto no tendrás todavía un entorno de desarrollo en que probarlo).

Pre-requisitos:

Conocimientos básicos de informática. Noción general sobre programación lado servidor de sitios web, y en particular los mecanismos de las interacciones cliente-servidor en sitios web.

Objetivo:

Ganar familiaridad con lo que es Express y cómo encaja con Node, qué funcionalidad proporciona y los pilares de construcción de una aplicación Express.

¿Qué son Express y Node?

Node (o más correctamente: Node.js) es un entorno que trabaja en tiempo de ejecución, de código abierto, multi-plataforma, que permite a los desarrolladores crear toda clase de herramientas de lado servidor y aplicaciones en JavaScript. La ejecución en tiempo real está pensada para usarse fuera del contexto de un explorador web (es decir, ejecutarse directamente en una computadora o sistema operativo de servidor). Como tal, el entorno omite las APIs de JavaScript específicas del explorador web y añade soporte para APIs de sistema operativo más tradicionales que incluyen HTTP y bibliotecas de sistemas de ficheros.

Desde una perspectiva de desarrollo de servidor web, Node tiene un gran número de ventajas:

  • ¡Gran rendimiento! Node ha sido diseñado para optimizar el rendimiento y la escalabilidad en aplicaciones web y es un muy buen complemento para muchos problemas comunes de desarrollo web (ej, aplicaciones web en tiempo real).
  • El código está escrito en "simple JavaScript", lo que significa que se pierde menos tiempo ocupándose de las "conmutaciones de contexto" entre lenguajes cuando estás escribiendo tanto el código del explorador web como del servidor.
  • JavaScript es un lenguaje de programación relativamente nuevo y se beneficia de los avances en diseño de lenguajes cuando se compara con otros lenguajes de servidor web tradicionales (ej, Python, PHP, etc.) Muchos otros lenguajes nuevos y populares se compilan/convierten a JavaScript de manera que puedes también usar CoffeeScript, ClosureScript, Scala, LiveScript, etc.
  • El gestor de paquetes de Node (NPM) proporciona acceso a cientos o miles de paquetes reusables. Tiene además la mejor en su clase resolución de dependencias y puede usarse para automatizar la mayor parte de la cadena de herramientas de compilación.
  • Es portable, con versiones que funcionan en Microsoft Windows, OS X, Linux, Solaris, FreeBSD, OpenBSD, WebOS, y NonStop OS. Además, está bien soportado por muchos de los proveedores de hospedaje web, que proporcionan infraestructura específica y documentación para hospedaje de sitios Node.
  • Tiene un ecosistema y comunidad de desarrolladores de terceros muy activa, con cantidad de gente deseosa de ayudar.

Puedes crear de sencilla un servidor web básico para responder cualquier petición simplemente usando el paquete HTTP de Node, como se muestra abajo. Este, creará un servidor y escuchará cualquier clase de peticiones en la URL http://127.0.0.1:8000/; cuando se reciba una petición, se responderá enviando en texto la respuesta: "Hola Mundo!".

// Se carga el módulo de HTTP
var http = require("http");

// Creación del servidor HTTP, y se define la escucha
// de peticiones en el puerto 8000
http.createServer(function(request, response) {

   // Se define la cabecera HTTP, con el estado HTTP (OK: 200) y el tipo de contenido
   response.writeHead(200, {'Content-Type': 'text/plain'});
   
   // Se responde, en el cuerpo de la respuesta con el mensaje "Hello World"
   response.end('Hola Mundo!\n');
}).listen(8000);

// Se escribe la URL para el acceso al servidor
console.log('Servidor en la url http://127.0.0.1:8000/');

Otras tareas comunes de desarrollo web no están directamente soportadas por el mismo Node. Si quieres añadir el manejo específico de diferentes verbos HTTP (ej, GET, POST, DELETE, etc.), gestionar de forma separada las peticiones por medio de diferentes direcciones URL ("rutas"), servir ficheros estáticos o usar plantillas para crear la respuesta de forma dinámica, necesitarás escribir el código por tí mismo, o ¡puedes evitar reinventar la rueda usando un framework web!

Express es el framework web más popular de Node, y es la librería subyacente para un gran número de otros frameworks web de Node populares. Proporciona mecanismos para:

  • Escritura de manejadores de peticiones con diferentes verbos HTTP en diferentes caminos URL (rutas).
  • Integración con motores de renderización de "vistas" para generar respuestas mediante la introducción de datos en plantillas.
  • Establecer ajustes de aplicaciones web como qué puerto usar para conectar, y la localización de las plantillas que se utilizan para renderizar la respuesta.
  • Añadir procesamiento de peticiones "middleware" adicional en cualquier punto dentro de la tubería de manejo de la petición.

A pesar de que Express es en sí mismo bastante minimalista, los desarrolladores han creado paquetes de middleware compatibles para abordar casi cualquier problema de desarrollo web. Hay librerías para trabajar con cookies, sesiones, inicios de sesión de usuario, parámetros URL, datos POST, cabeceras de seguridad y muchos más. Puedes encontrar una lista de paquetes middleware mantenida por el equipo de Express en Express Middleware (junto con una lista de algunos de los paquetes más populares de terceros).

Nota: esta flexibilidad es una espada de doble filo. Hay paquetes de middleware para abordar casi cualquier problema o requerimiento, pero deducir cuáles son los paquetes adecuados a usar algunas veces puede ser un auténtico reto. Tampoco hay una "forma correcta" de estructurar una aplicación, y muchos ejemplos que puedes encontrar en la Internet no son óptimos, o sólo muestran una pequeña parte de lo que necesitas hacer para desarrollar una aplicación web.

¿De dónde vino?

Node fué lanzado inicialmente, sólo para Linux, en 2009. El gestor de paquetes NPM fué lanzado en 2010, y el soporte nativo para Windows fue añadido en 2012. La versión actual LTS (Long Term Suppport) es Node v8.9.3 mientras que la última versión es Node 9. Ésto es sólo una pequeña foto de una historia muy rica; profundiza en Wikipedia si quieres saber más).

Express fue lanzado inicialmente en Noviembre de 2010 y está ahora en la versión 4.16 de la API. Puedes comprobar en el changelog la información sobre cambios en la versión actual, y en GitHub notas de lanzamiento históricas más detalladas.

¿Qué popularidad tiene Node/Express?

La popularidad de un framework web es importante porque es un indicador de se continuará manteniendo y qué recursos tienen más probabilidad de estar disponibles en términos de documentación, librerías de extensiones y soporte técnico.

No existe una medida disponible de inmediato y definitiva de la popularidad de los frameworks de lado servidor (aunque sitios como Hot Frameworks intentan asesorar sobre popularidad usando mecanismos como contar para cada plataforma el número de preguntas sobre proyectos en GitHub y StackOverflow). Una pregunta mejor es si Node y Express son lo "suficientemente populares" para evitar los problemas de las plataformas menos populares. ¿Continúan evolucionando? ¿Puedes conseguir la ayuda que necesitas? ¿Hay alguna posibilidad de que consigas un trabajo remunerado si aprendes Express?

De acuerdo con el número de compañías de perfil alto que usan Express, el número de gente que contribuye al código base, y el número de gente que proporciona soporte tanto libre como pagado, podemos entonces decir que sí, !Express es un framework popular!

¿Es Express dogmático?

Los frameworks web frecuentemente se refieren a sí mismos como "dogmáticos" ("opinionated") o "no dogmáticos" ("unopinionated").

Los frameworks dogmáticos son aquellos que opinan acerca de la "manera correcta" de gestionar cualquier tarea en particular. Ofrecen soporte para el desarrollo rápido en un dominio en particular (resolver problemas de un tipo en particular) porque la manera correcta de hacer cualquier cosa está generalmente bien comprendida y bien documentada.Sin embargo pueden ser menos flexibles para resolver problemas fuera de su dominio principal, y tienden a ofrecer menos opciones para elegir qué componentes y enfoques pueden usarse.

Los framewoks no dogmáticos, en contraposición, tienen muchas menos restricciones sobre el modo mejor de unir componentes para alcanzar un objetivo, o incluso qué componentes deberían usarse. Hacen más fácil para los desarrolladores usar las herramientas más adecuadas para completar una tarea en particular, si bien al coste de que necesitas encontrar esos componentes por tí mismo.

Express es no dogmático, transigente. Puedes insertar casi cualquier middleware compatible que te guste dentro de la cadena de manejo de la petición, en casi cualquier orden que te apetezca. Puedes estructurar la app en un fichero o múltiples ficheros y usar cualquier estructura de directorios. ¡Algunas veces puedes sentir que tienes demasiadas opciones!

¿Cómo es un código para Express?

En sitios web o aplicaciones web dinámicas, que accedan a bases de datos, el servidor espera a recibir peticiones HTTP del navegador (o cliente). Cuando se recibe una petición, la aplicación determina cuál es la acción adecuada correspondiente, de acuerdo a la estructura de la URL y a la información (opcional) indicada en la petición con los métodos POSTGET. Dependiendo de la acción a realizar, puede que se necesite leer o escribir en la base de datos, o realizar otras acciones necesarias para atender la petición correctamente. La aplicación ha de responder al navegador, normalmente, creando una página HTML dinámicamente para él, en la que se muestre la información pedida, usualmente dentro de un elemento especifico para este fin, en una plantilla HTML.

Express posee métodos para especificar que función ha de ser llamada dependiendo del verbo HTTP usado en la petición (GET, POST, SET, etc.) y la estructura de la URL ("ruta"). También tiene los métodos para especificar que plantilla ("view") o gestor de visualización utilizar, donde están guardadas las plantillas de HTML que han de usarse  y como  generar la visualización adecuada para cada caso. El middleware de Express, puede usarse también para añadir funcionalidades para la gestión de cookies, sesiones y usuarios, mediante el uso de parámetros, en los métodos POST/GET.  Puede utilizarse además cualquier sistema de trabajo con bases de datos, que sea soportado por Node (Express  no especifica ningún método preferido para trabajar con bases de datos). 

En las siguientes secciones, se explican algunos puntos comunes que se pueden encontrar cuando se trabaja con código de Node y Express.

Helloworld Express

First lets consider the standard Express Hello World example (we discuss each part of this below, and in the following sections).

Tip: If you have Node and Express already installed (or if you install them as shown in the next article), you can save this code in a file called app.js and run it in a command prompt by calling node app.js.

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

app.get('/', function(req, res) {
  res.send('Hello World!');
});

app.listen(3000, function() {
  console.log('Example app listening on port 3000!');
});

The first two lines require() (import) the express module and create an Express application. This object, which is traditionally named app, has methods for routing HTTP requests, configuring middleware, rendering HTML views, registering a template engine, and modifying application settings that control how the application behaves (e.g. the environment mode, whether route definitions are case sensitive, etc.)

The middle part of the code (the three lines starting with app.get) shows a route definition. The app.get() method specifies a callback function that will be invoked whenever there is an HTTP GET request with a path ('/') relative to the site root. The callback function takes a request and a response object as arguments, and simply calls send() on the response to return the string "Hello World!"

The final block starts up the server on port '3000' and prints a log comment to the console. With the server running, you could go to localhost:3000 in your browser to see the example response returned.

Importing and creating modules

A module is a JavaScript library/file that you can import into other code using Node's require() function. Express itself is a module, as are the middleware and database libraries that we use in our Express applications.

The code below shows how we import a module by name, using the Express framework as an example. First we invoke the require() function, specifying the name of the module as a string ('express'), and calling the returned object to create an Express application. We can then access the properties and functions of the application object.

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

You can also create your own modules that can be imported in the same way.

Tip: You will want to create your own modules, because this allows you to organise your code into managable parts — a monolithic single-file application is hard to understand and maintain. Using modules also helps you manage your namespace, because only the variables you explicitly export are imported when you use a module.

To make objects available outside of a module you just need to assign them to the exports object. For example, the square.js module below is a file that exports area() and perimeter() methods:

exports.area = function(width) { return width * width; };
exports.perimeter = function(width) { return 4 * width; };

We can import this module using require(), and then call the exported method(s) as shown:

var square = require('./square'); // Here we require() the name of the file without the (optional) .js file extension
console.log('The area of a square with a width of 4 is ' + square.area(4));

Note: You can also specify an absolute path to the module (or a name, as we did initially).

If you want to export a complete object in one assignment instead of building it one property at a time, assign it to module.exports as shown below (you can also do this to make the root of the exports object a constructor or other function):

module.exports = {
  area: function(width) {
    return width * width;
  },
       
  perimeter: function(width) {
    return 4 * width;
  }
};

For a lot more information about modules see Modules (Node API docs).

Using asynchronous APIs

JavaScript code frequently uses asynchronous rather than synchronous APIs for operations that may take some time to complete. A synchronous API is one in which each operation must complete before the next operation can start. For example, the following log functions are synchronous, and will print the text to the console in order (First, Second).

console.log('First');
console.log('Second');

By contrast, an asynchronous API is one in which the API will start an operation and immediately return (before the operation is complete). Once the operation finishes, the API will use some mechanism to perform additional operations. For example, the code below will print out "Second, First" because even though setTimeout() method is called first, and returns immediately, the operation doesn't complete for several seconds.

setTimeout(function() {
   console.log('First');
   }, 3000);
console.log('Second');

Using non-blocking asynchronous APIs is even more important on Node than in the browser, because Node is a single threaded event-driven execution environment. "single threaded" means that all requests to the server are run on the same thread (rather than being spawned off into separate processes). This model is extremely efficient in terms of speed and server resources, but it does mean that if any of your functions call synchronous methods that take a long time to complete, they will block not just the current request, but every other request being handled by your web application.

There are a number of ways for an asynchronous API to notify your application that it has completed. The most common way is to register a callback function when you invoke the asynchronous API, that will be called back when the operation completes. This is the approach used above.

Tip: Using callbacks can be quite "messy" if you have a sequence of dependent asynchronous operations that must be performed in order, because this results in multiple levels of nested callbacks. This problem is commonly known as "callback hell". This problem can be reduced by good coding practices (see http://callbackhell.com/), using a module like async, or even moving to ES6 features like Promises.

Note: A common convention for Node and Express is to use error-first callbacks. In this convention the first value in your callback functions is an error value, while subsequent arguments contain success data. There is a good explanation of why this approach is useful in this blog: The Node.js Way - Understanding Error-First Callbacks (fredkschott.com).

Creating route handlers

In our Hello World Express example (see above), we defined a (callback) route handler function for HTTP GET requests to the site root ('/').

app.get('/', function(req, res) {
  res.send('Hello World!');
});

The callback function takes a request and a response object as arguments. In this case the method simply calls send() on the response to return the string "Hello World!" There are a number of other response methods for ending the request/response cycle, for example you could call res.json() to send a JSON response or res.sendFile() to send a file.

JavaScript tip: You can use any argument names you like in the callback functions; when the callback is invoked the first argument will always be the request and the second will always be the response. It makes sense to name them such that you can identify the object you're working with in the body of the callback.

The Express application object also provides methods to define route handlers for all the other HTTP verbs, which are mostly used in exactly the same way: post(), put(), delete(), options(), trace(), copy(), lock(), mkcol(), move(), purge(), propfind(), proppatch(), unlock(), report(), mkactivity(), checkout(), merge(), m-search(), notify(), subscribe(), unsubscribe(), patch(), search(), and connect().

There is a special routing method, app.all(), which will be called in response to any HTTP method. This is used for loading middleware functions at a particular path for all request methods. The following example (from the Express documentation) shows a handler that will be executed for requests to /secret irrespective of the HTTP verb used (provided it is supported by the http module).

app.all('/secret', function(req, res, next) {
  console.log('Accessing the secret section ...');
  next(); // pass control to the next handler
});

Routes allow you to match particular patterns of characters in a URL, and extract some values from the URL and pass them as parameters to the route handler (as attributes of the request object passed as a parameter).

Often it is useful to group route handlers for a particular part of a site together and access them using a common route-prefix (e.g. a site with a Wiki might have all wiki-related routes in one file and have them accessed with a route prefix of /wiki/). In Express this is achieved by using the express.Router object. For example, we can create our wiki route in a module named wiki.js, and then export the Router object, as shown below:

// wiki.js - Wiki route module

var express = require('express');
var router = express.Router();

// Home page route
router.get('/', function(req, res) {
  res.send('Wiki home page');
});

// About page route
router.get('/about', function(req, res) {
  res.send('About this wiki');
});

module.exports = router;

Note: Adding routes to the Router object is just like adding routes to the app object (as shown previously).

To use the router in our main app file we would then require() the route module (wiki.js), then call use() on the Express application to add the Router to the middleware handling path. The two routes will then be accessible from /wiki/ and /wiki/about/.

var wiki = require('./wiki.js');
// ...
app.use('/wiki', wiki);

We'll show you a lot more about working with routes, and in particular about using the Router, later on in the linked section Routes and controllers .

Using middleware

Middleware is used extensively in Express apps, for tasks from serving static files to error handling, to compressing HTTP responses. Whereas route functions end the HTTP request-response cycle by returning some response to the HTTP client, middleware functions typically perform some operation on the request or response and then call the next function in the "stack", which might be more middleware or a route handler. The order that middleware is called is up to the app developer.

Note: The middleware can perform any operation, execute any code, make changes to the request and response object, and it can also end the request-response cycle. If it does not then end the cycle it must call next() to pass control to the next middleware function (or the request will be left hanging).

Most apps will use third-party middleware in order to simplify common web development tasks like working with cookies, sessions, user authentication, accessing request POST and JSON data, logging, etc. You can find a list of middleware packages maintained by the Express team (which also includes other popular 3rd party packages). Other Express packages are available on the NPM package manager.

To use third party middleware you first need to install it into your app using NPM. For example, to install the morgan HTTP request logger middleware, you'd do this:

$ npm install morgan

You could then call use() on the Express application object to add the middleware to the stack:

var express = require('express');
var logger = require('morgan');
var app = express();
app.use(logger('dev'));
...

Note: Middleware and routing functions are called in the order that they are declared. For some middleware the order is important (for example if session middleware depends on cookie middleware, then the cookie handler must be added first). It is almost always the case that middleware is called before setting routes, or your route handlers will not have access to functionality added by your middleware.

You can write your own middleware functions, and you are likely to have to do so (if only to create error handling code). The only difference between a middleware function and a route handler callback is that middleware functions have a third argument next, which middleware functions are expected to call if they do not complete the request cycle (when the middleware function is called, this contains the next function that must be called).

You can add a middleware function to the processing chain with either app.use() or app.add(), depending on whether you want to apply the middleware to all responses or to responses with a particular HTTP verb (GET, POST, etc). You specify routes the same in both cases, though the route is optional when calling app.use().

The example below shows how you can add the middleware function using both methods, and with/without a route.

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

// An example middleware function
var a_middleware_function = function(req, res, next) {
  // ... perform some operations
  next(); // Call next() so Express will call the next middleware function in the chain.
}

// Function added with use() for all routes and verbs
app.use(a_middleware_function);

// Function added with use() for a specific route
app.use('/someroute', a_middleware_function);

// A middleware function added for a specific HTTP verb and route
app.get('/', a_middleware_function);

app.listen(3000);

JavaScript Tip: Above we declare the middleware function separately and then set it as the callback. In our previous route handler function we declared the callback function when it was used. In JavaScript, either approach is valid.

The Express documentation has a lot more excellent documentation about using and writing Express middleware.

Serving static files

You can use the express.static middleware to serve static files, including your images, CSS and JavaScript (static() is the only middleware function that is actually part of Express). For example, you would use the line below to serve images, CSS files, and JavaScript files from a directory named 'public' at the same level as where you call node:

app.use(express.static('public'));

Any files in the public directory are served by adding their filename (relative to the base "public" directory) to the base URL. So for example:

http://localhost:3000/images/dog.jpg
http://localhost:3000/css/style.css
http://localhost:3000/js/app.js
http://localhost:3000/about.html

You can call static() multiple times to serve multiple directories. If a file cannot be found by one middleware function then it will simply be passed on to the subsequent middleware (the order that middleware is called is based on your declaration order).

app.use(express.static('public'));
app.use(express.static('media'));

You can also create a virtual prefix for your static URLs, rather than having the files added to the base URL. For example, here we specify a mount path so that the files are loaded with the prefix "/media":

app.use('/media', express.static('public'));

Now, you can load the files that are in the public directory from the /media path prefix.

http://localhost:3000/media/images/dog.jpg
http://localhost:3000/media/video/cat.mp4
http://localhost:3000/media/cry.mp3

For more information, see Serving static files in Express.

Handling errors

Errors are handled by one or more special middleware functions that have four arguments, instead of the usual three: (err, req, res, next). For example:

app.use(function(err, req, res, next) {
  console.error(err.stack);
  res.status(500).send('Something broke!');
});

These can return any content required, but must be called after all other app.use() and routes calls so that they are the last middleware in the request handling process!

Express comes with a built-in error handler, which takes care of any remaining errors that might be encountered in the app. This default error-handling middleware function is added at the end of the middleware function stack. If you pass an error to next() and you do not handle it in an error handler, it will be handled by the built-in error handler; the error will be written to the client with the stack trace.

Note: The stack trace is not included in the production environment. To run it in production mode you need to set the the environment variable NODE_ENV to 'production'.

Note: HTTP404 and other "error" status codes are not treated as errors. If you want to handle these, you can add a middleware function to do so. For more information see the FAQ.

For more information see Error handling (Express docs).

Using databases

Express apps can use any database mechanism supported by Node (Express itself doesn't define any specific additional behaviour/requirements for database management). There are many options, including PostgreSQL, MySQL, Redis, SQLite, MongoDB, etc.

In order to use these you have to first install the database driver using NPM. For example, to install the driver for the popular NoSQL MongoDB you would use the command:

$ npm install mongodb

The database itself can be installed locally or on a cloud server. In your Express code you require the driver, connect to the database, and then perform create, read, update, and delete (CRUD) operations. The example below (from the Express documentation) shows how you can find "mammal" records using MongoDB.

var MongoClient = require('mongodb').MongoClient;

MongoClient.connect('mongodb://localhost:27017/animals', function(err, db) {
  if (err) throw err;

  db.collection('mammals').find().toArray(function (err, result) {
    if (err) throw err;

    console.log(result);
  });
});

Another popular approach is to access your database indirectly, via an Object Relational Mapper ("ORM"). In this approach you define your data as "objects" or "models" and the ORM maps these through to the underlying database format. This approach has the benefit that as a developer you can continue to think in terms of JavaScript objects rather than database semantics, and that there is an obvious place to perform validation and checking of incoming data. We'll talk more about databases in a later article.

For more information see Database integration (Express docs).

Rendering data (views)

Template engines (referred to as "view engines" by Express) allow you to specify the structure of an output document in a template, using placeholders for data that will be filled in when a page is generated. Templates are often used to create HTML, but can also create other types of document. Express has support for a number of template engines, and there is a useful comparison of the more popular engines here: Comparing JavaScript Templating Engines: Jade, Mustache, Dust and More.

In your application settings code you set the template engine to use and the location where Express should look for templates using the 'views' and 'view engines' settings, as shown below (you will also have to install the package containing your template library too!)

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

// Set directory to contain the templates ('views')
app.set('views', path.join(__dirname, 'views'));

// Set view engine to use, in this case 'some_template_engine_name'
app.set('view engine', 'some_template_engine_name');

The appearance of the template will depend on what engine you use. Assuming that you have a template file named "index.<template_extension>" that contains placeholders for data variables named 'title' and "message", you would call Response.render() in a route handler function to create and send the HTML response:

app.get('/', function(req, res) {
  res.render('index', { title: 'About dogs', message: 'Dogs rock!' });
});

For more information see Using template engines with Express (Express docs).

File structure

Express makes no assumptions in terms of structure or what components you use. Routes, views, static files, and other application-specific logic can live in any number of files with any directory structure. While it is perfectly possible to have the whole Express application in one file, typically it makes sense to split your application into files based on function (e.g. account management, blogs, discussion boards) and architectural problem domain (e.g. model, view or controller if you happen to be using an MVC architecture).

In a later topic we'll use the Express Application Generator, which creates a modular app skeleton that we can easily extend for creating web applications.

Summary

Congratulations, you've completed the first step in your Express/Node journey! You should now understand Express and Node's main benefits, and roughly what the main parts of an Express app might look like (routes, middleware, error handling, and template code). You should also understand that with Express being an unopinionated framework, the way you pull these parts together and the libraries that you use are largely up to you!

Of course Express is deliberately a very lightweight web application framework, so much of its benefit and potential comes from third party libraries and features. We'll look at those in more detail in the following articles. In our next article we're going to look at setting up a Node development environment, so that you can start seeing some Express code in action.

See also

In this module

Etiquetas y colaboradores del documento

 Colaboradores en esta página: Sergio_Gonzalez_Collado, javierdelpino, SphinxKnight
 Última actualización por: Sergio_Gonzalez_Collado,