Tags: frontend

Earlier this year, I wrote about an accessibility issue I was having on The Session. Specifically, it was an issue with Ajax and pagination. But I managed to sort it out, and the lesson was very clear:

As is so often the case, the issue was with me trying to be too clever with ARIA, and the solution was to ease up on adding so many ARIA attributes.

Well, fast forward to the past few weeks, when I was contacted by one of the screen-reader users on The Session. There was, once again, a problem with the Ajax pagination, specifically with VoiceOver on iOS. The first page of results were read out just fine, but subsequent pages were not only never announced, the content was completely unavailable. The first page of results would’ve been included in the initial HTML, but the subsequent pages of results are injected with JavaScript (if JavaScript is available—otherwise it’s regular full-page refreshes all the way).

This pagination pattern shows up all over the site: lists of what’s new, search results, and more. I turned on VoiceOver and I was able to reproduce the problem straight away.

I started pulling apart my JavaScript looking for the problem. Was it something to do with how I was handling focus? I just couldn’t figure it out. And other parts of the site that used Ajax didn’t seem to be having the same problem. I was mystified.

Finally, I tracked down the problem, and it wasn’t in the JavaScript at all.

Wherever the pagination pattern appears, there are “previous” and “next” links, marked up with the appropriate rel="prev" and rel="next" attributes. Well, apparently past me thought it would be clever to add some ARIA attributes in there too. My thinking must’ve been something like this:

• Those links control the area of the page with the search results.
• That area of the page has an ID of “results”.
• I should add aria-controls="results" to those links.

That was the problem …which is kind of weird, because VoiceOver isn’t supposed to have any support for aria-controls. Anyway, once I removed that attribute from the links, everything worked just fine.

Just as the solution last time was to remove the aria-atomic attribute on the updated area, the solution this time was to remove the aria-controls attribute on the links that trigger the update. Maybe this time I’ll learn my lesson: don’t mess with ARIA attributes you don’t understand.

I’ve found that the older I get, the less I care about looking stupid. This is remarkably freeing. I no longer have any hesitancy about raising my hand in a meeting to ask “What’s that acronym you just mentioned?” This sometimes has the added benefit of clarifying something for others in the room who might have been to shy to ask.

I remember a few years back being really confused about npm. Fortunately, someone who was working at npm at the time came to Brighton for FFConf, so I asked them to explain it to me.

As I understood it, npm was intended to be used for managing packages of code for Node. Wasn’t it actually called “Node Package Manager” at one point, or did I imagine that?

Anyway, the mental model I had of npm was: npm is to Node as PEAR is to PHP. A central repository of open source code projects that you could easily add to your codebase …for your server-side code.

But then I saw people talking about using npm to manage client-side JavaScript. That really confused me. That’s why I was asking for clarification.

It turns out that my confusion was somewhat warranted. The npm project had indeed started life as a repo for server-side code but had since expanded to encompass client-side code too.

I understand how it happened, but it confirmed a worrying trend I had noticed. Developers were writing front-end code as though it were back-end code.

On the one hand, that makes total sense when you consider that the code is literally in the same programming language: JavaScript.

On the other hand, it makes no sense at all! If your code’s run-time is on the server, then the size of the codebase doesn’t matter that much. Whether it’s hundreds or thousands of lines of code, the execution happens more or less independentally of the network. But that’s not how front-end development works. Every byte matters. The more code you write that needs to be executed on the user’s device, the worse the experience is for that user. You need to limit how much you’re using the network. That means leaning on what the browser gives you by default (that’s your run-time environment) and keeping your code as lean as possible.

Dave echoes my concerns in his end-of-the-year piece called The Kind of Development I Like:

I now think about npm and wonder if it’s somewhat responsible for some of the pain points of modern web development today. Fact is, npm is a server-side technology that we’ve co-opted on the client and I think we’re feeling those repercussions in the browser.

Writing back-end and writing front-end code require very different approaches, in my opinion. But those differences have been erased in “modern” JavaScript.

The Unix Philosophy encourages us to write small micro libraries that do one thing and do it well. The Node.js Ecosystem did this in spades. This works great on the server where importing a small file has a very small cost. On the client, however, this has enormous costs.

In a funny way, this situation reminds me of something I saw happening over twenty years ago. Print designers were starting to do web design. They had a wealth of experience and knowledge around colour theory, typography, hierarchy and contrast. That was all very valuable to bring to the world of the web. But the web also has fundamental differences to print design. In print, you can use as many typefaces as you want, whereas on the web, to this day, you need to be judicious in the range of fonts you use. But in print, you might have to limit your colour palette for cost reasons (depending on the printing process), whereas on the web, colours are basically free. And then there’s the biggest difference of all: working within known dimensions of a fixed page in print compared to working within the unknowable dimensions of flexible viewports on the web.

Fast forward to today and we’ve got a lot of Computer Science graduates moving into front-end development. They’re bringing with them a treasure trove of experience in writing robust scalable code. But web browsers aren’t like web servers. If your back-end code is getting so big that it’s starting to run noticably slowly, you can throw more computing power at it by scaling up your server. That’s not an option on the front-end where you don’t really have one run-time environment—your end users have their own run-time environment with its own constraints around computing power and network connectivity.

That’s a very, very challenging world to get your head around. The safer option is to stick to the mental model you’re familiar with, whether you’re a print designer or a Computer Science graduate. But that does a disservice to end users who are relying on you to deliver a good experience on the World Wide Web.