This article continues a series about the most recent addition to Linux Professional Institute certifications: Web Development Essentials. The first part introduced the skills that make you a web developer; now we’ll look at the technologies required for each piece of the web experience, shown in Figure 1.
CSS stands for Cascading Style Sheets. The term “cascading” is important, indicating that some rules override others. You have to know how to apply your effects at different levels of HTML (entities, IDs), and which rules override others. You also need to work with positioning. For instance, you can make bullets within ordered lists look different from bullets within unordered lists. CSS works tightly with HTML.
By now, you should go beyond simple exercises on your computer and get real-world experience. You will grasp the power of the technologies discussed in this article, and understand how best to use each one, if you can work on a site with dozens of web pages and many elements. You might be able to work in this environment by volunteering for a non-profit organization or a friend who is willing to entrust you with the creation or maintenance of their web site.
Production environments employ sophisticated web servers with their own administrative needs. One of the conveniences of Express is that it lets you run a server on your desktop or laptop without having to install and configure more software. That’s how you can prepare for and take the Web Development Essentials exam.
When a request comes into the server from a client, the server invokes a Node.js program to handle the request. You need to unpack the arguments (user data) in the request, check the arguments to make sure they contain no malicious content, and return results as HTML.
Express offers templates to make it easy to create consistent HTML-based pages; Web Development Essentials expects some familiarity with Express templates.
The next article in this series wraps it up with a discussion of the last piece of Figure 1, the database.