10 Common Mistakes Web Developers Make
1) Writing Old School HTMLMistake: The early days of the internet had much fewer options for markup than we do today. However, old habits die hard, and many still write their HTML as if we were still in the 20th century. Examples here are using <table> elements for layout , <span> or <div> elements when other semantic-specific tags would be more appropriate, or using tags that are not supported in current HTML standard such as <center> or <font>, or spacing items on a page with a large number of entities. Impact: Writing last decade's HTML can result in an overly complicated markup that will behave inconsistently across multiple browsers. And it's not necessary for more recent modern browsers like Microsoft Edge and even past versions of Internet Explorer (11, 10, 9). How to avoid: Stop using <table> element for the layout of content, and limit usage for it to displaying tabular data. Get acquainted with the current markup options available such as seen at whatwg.org. Use HTML to describe what the content is, not how it will be displayed. To display your content correctly, use CSS (http://www.w3.org/Style/CSS/).
2) "It works in my browser."Mistake: A developer may be fond of a particular browser or really despise one, and might primarily test web pages with that bias in view. It is also possible that code samples found online may be written without factoring how it would render in other browsers. Also, some browsers have different default values for styles. Impact: Writing a browser-centric site will likely result in very poor quality when displayed in other browsers. How to avoid: It would not be practical to test web pages in every browser & version during development. However, having a regular interval of checking how your site will appear in multiple browsers is a good approach. Nowadays free tools to help are readily available regardless of your preferred platform: free VMs, site scanners. Sites such as http://browsershots.org/ or https://www.browserstack.com/ show snapshots of how a given page would render over multiple browsers/versions/platforms. Tools such as Visual Studio can also invoke multiple browsers to display a single page you are working on. When designing with CSS, consider "resetting" all the defaults as shown at meyerweb.com. If your site is using any CSS features created specific for a browser, be cautious as to how you will approach vendor prefixes such as -webkit-, -moz-, or -ms-. For guidance on industry trends in this regard, it would be worth your time to examine the following references:
- Microsoft Edge Dev Blog: A break from the past, part 2: Saying goodbye to ActiveX, VBScript, attachEventÉ
- QuirksMode.org: CSS vendor prefixes considered harmful
- Bruce Lawson: On Internet Explorer supporting -webkit- vendor prefixes
3) Bad FormMistake: Prompting a user to provide any information (especially when entered into a text field) and assuming the data will be received as intended. Impact: Many things can (and likely will) go wrong when user entry is trusted. Pages may fail if required data is not provided, or data received is not compatible with an underlying data scheme. Even more serious is the intentional violation of the site's database, perhaps through Injection attacks (see OWASP: Top 10 2013-A1-Injections). How to avoid: The first bit of advice here is to make sure it is clear to the user what type of data you are looking for. These days, asking for an address could result in either a business, home, or even email address! In addition to be specific, take advantage of data validation techniques available in today's HTML as seen in this article. No matter how data is validated on the browser side, be sure it is always validated on the server-side as well. Never allow a concatenated T-SQL statement to use data from user entry without a confirmation that each field is the type of data it should be.
- Ask yourself: "Are all my graphics absolutely necessary?" If not, remove unneeded images. You can scan your site here for suggestion on which images to compress.
- Minimize the file size of your images with tools such as Shrink O'Matic or RIOT.
- Preload images. This will not improve the cost on initial download, but can make other pages on the site that use the images load much faster. For tips on this, see this article.
6) Writing Forking CodeMistake: With the noble notion of supporting all browsers and versions, a developer creates code to respond to each possible scenario. The code becomes a heap of if statements, forking in all sorts of direction. Impact: As new versions of browsers update, management of code files become bulky and difficult to manage. And as mentioned in #1, it's increasingly unnecessary. How to avoid: Implement feature detection in code versus browser/version detection. Feature detection techniques not only dramatically reduce the amount of code, but it is also much easier to read and manage. Consider using a library such as Modernizr, which not only helps with feature detection. It also automatically helps provide fallback support for older browsers not up to speed with HTML5 or CSS3.
7) Designing UnresponsivelyMistake: Site development assumes viewing in the same size monitor as the developer/designer. Impact: When viewing the site on mobile devices or very large screens, the user experience suffers from either not being able to see important aspects of the page or even preventing navigation to other pages. How to avoid: Think responsively. Use responsive design (Wikipedia) or (A List Apart article) on your sites. Here are some practical tutorials on it including responsive images. A very popular library ready to serve in this area is Bootstrap.
8) Making Meaningless PagesMistake: Producing public facing pages with content that might be very useful, but not providing any hints to search engines. Accessibility features are not implemented. Impact: Pages are not as discoverable through search engines and therefore may receive little or no visits. The page content may be very cryptic to users with impaired vision. How to avoid: Use SEO (search engine optimizations) and support accessibility in HTML. Regarding SEO, be sure to add <meta> tags to provide meaning to a page with keywords and description. A good write up on that can be found at About Tech. To enable a better accessibility experience, be determined to provide an alt="your image description" attribute in each of your <img> or <area> tags. Of course, there is more to do, and further suggestions can be investigated at About Tech. You can also test a public web page at Cynthia Says to see if it is compliant with Section 508.
10) Working Too MuchMistake: A developer spends a long time creating web content. Time might be spent doing repetitive tasks, or just typing a lot. Impact: Time for initial website launch or subsequent updates is too lengthy. The value of the developer diminishes when it appears other developers are doing comparable work in less time and with less effort. Manual labor is prone to mistakes, and troubleshooting errors takes even more time. How to avoid: Explore your options. Consider using new tools or new process techniques for every stage of development. For example, how does your current code editor compare to Sublime Text or Visual Studio? Regardless of what code editor you are using, have you recently dived into its features? Perhaps a small investment of your time perusing the documentation could unveil a new way to do something that could save hours & hours of time later. For example, note how an extension to Visual Studio can increase productivity for web developers as seen in this post. Don't miss out on tools available on the web to help! For example, check out the tools at dev.modern.ie to simplify testing (across multiple platforms and devices) and troubleshooting. You can also help reduce time and mistakes by automating processes. An example of this is using a tool like Grunt that can automate things such as the minifying of files (see mistake #4). Another example is Bower, which can help manage libraries/frameworks (see mistake #9). How about the web server itself? With the help of services such as Microsoft Azure Web Apps, you can quickly create a site for virtually any development scenario that can easily scale with your business!
SummaryBy identifying common mistakes, web developers can eliminate much frustration that others have already endured. Not only is it important to acknowledge, but when we understand the impact of a mistake and take measures to avoid it, we can create a development process catered to our preferences Ð and do so with confidence!
- Scan your site for out-of-date libraries, layout issues, and accessibility
- Use virtual machines for Mac, Linux, and Windows
- Remotely test for Microsoft Edge on your own device
- Coding Lab on GitHub: Cross-browser testing and best practices
- Woah, I can test Edge & IE on a Mac & Linux! (from Rey Bango)
- The Edge Rendering Engine that makes the Web just work (from Jacob Rossi)
- Unleash 3D rendering with WebGL (from David Catuhe including the vorlon.JS and babylonJS projects)
- Hosted web apps and web platform innovations (from Kevin Hill and Kiril Seksenov including the manifold.JS project)