Express Web Framework (Node.js/JavaScript)

Express is a popular unopinionated web framework, written in JavaScript and hosted within the node.js runtime environment. The module explains some of the key benefits of this framework, how to set up your development environment and how to perform common web development and deployment tasks.


Before starting this module you will need to understand what server-side web programming and web frameworks are, ideally by reading the topics in our Server-side website programming first steps module. A general knowledge of programming concepts and JavaScript is highly recommended, but not essential to understanding the core concepts.

Note: This website has many useful resources for learning JavaScript in the context of client-side development: JavaScriptJavaScript Guide, JavaScript BasicsJavaScript (learning). The core JavaScript language and concepts are the same for server-side development on Node.js and this material will be relevant. Node.js offers additional APIs for supporting functionality that is useful in browserless environments, e.g. to create HTTP servers and access the file system, but does not support JavaScript APIs for working with the browser and DOM.

This guide will provide some information about working with Node.js and Express, and there are numerous other excellent resources on the Internet and in books — some of these linked from How do I get started with Node.js (StackOverflow) and What are the best resources for learning Node.js? (Quora).


Express/Node introduction
In this first Express article we answer the questions "What is Node?" and "What is Express?" and give you an overview of what makes the Express web framework special. We'll outline the main features, and show you some of the main building blocks of an Express application (although at this point you won't yet have a development environment in which to test it).
Setting up a Node (Express) development environment
Now that you know what Express is for, we'll show you how to set up and test a Node/Express development environment on Windows, Linux (Ubuntu), and Mac OS X. Whatever common operating system you are using, this article should give you what you need to be able to start developing Express apps.
Express Tutorial: The Local Library website
The first article in our practical tutorial series explains what you'll learn, and provides an overview of the "local library" example website we'll be working through and evolving in subsequent articles.
Express Tutorial Part 2: Creating a skeleton website
This article shows how you can create a "skeleton" website project, which you can then go on to populate with site-specific routes, templates/views, and databases.
Express Tutorial Part 3: Using a Database (with Mongoose)
This article briefly introduces databases for Node/Express. It then goes on to show how we can use Mongoose to provide database access for the LocalLibrary website. It explains how object schema and models are declared, the main field types, and basic validation. It also briefly shows a few of the main ways you can access model data.
Express Tutorial Part 4: Routes and controllers
In this tutorial we'll set up routes (URL handling code) with "dummy" handler functions for all the resource endpoints that we'll eventually need in the LocalLibrary website. On completion, we'll have a modular structure for our route handling code, that we can extend with real handler functions in the following articles. We'll also have a really good understanding of how to create modular routes using Express.
Express Tutorial Part 5: Displaying library data
We're now ready to add the pages that display the LocalLibrary website books and other data. The pages will include a home page that shows how many records we have of each model type, and list and detail pages for all of our models. Along the way we'll gain practical experience in getting records from the database, and using templates.
Express Tutorial Part 6: Working with forms
In this tutorial we'll show you how to work with HTML Forms in Express, using Pug, and in particular how to write forms to create, update, and delete documents from the database.
Express Tutorial Part 7: Deploying to production
Now you've created an awesome LocalLibrary website, you're going to want to install it on a public web server so that it can be accessed by library staff and members over the Internet. This article provides an overview of how you might go about finding a host to deploy your website, and what you need to do in order to get your site ready for production.

See also

Installing LocalLibrary on PWS/Cloud Foundry
This article provides a practical demonstration of how to install LocalLibrary on the Pivotal Web Services PaaS cloud — this is a full-featured, open source alternative to Heroku, the PaaS cloud service used in Part 7 of the tutorial, listed above. PWS/Cloud Foundry is definitely worth checking out if you are looking for an alternative to Heroku (or another PaaS cloud service), or simply feel like trying something different.

Adding more tutorials

That's the end of the tutorial articles (for now). If you would like to extend it, other interesting topics to cover are:

  • Using sessions
  • User authentication
  • User authorisation and permissions
  • Testing an Express web application
  • Web security for Express web applications.

And of course it would be excellent to have an assessment task!

Document Tags and Contributors

 Contributors to this page: chrisdavidmills, Laassari, JonathanPool, hamishwillee
 Last updated by: chrisdavidmills,