I’ve been writing WordPress plug-ins for a while now — I launched my first plug-in a little more than 3 years ago. I’ve been involved in web site accessibility for about seven years. Naturally, when I started writing WordPress plug-ins, making them accessible was part of my goal. But accessible software extensions have two aspects: the interface, and the output: and I don’t have complete control over either.

Is it possible to make a plug-in with accessible output, guaranteed, every time? Is that compatible with a desire to provide flexible software which developers can use for a wide variety of possible needs from a design and functionality perspective?

What I’ve found is that I can unquestionably make a plug-in which is capable of creating accessible content. However, I’ve also discovered that in order to really make a plug-in flexible, it can’t have too rigid of an output: it needs to allow the user to customize the structure and content at a pretty significant level.

As a web site developer, this is certainly something I always want: whenever I find myself using a plug-in which doesn’t have built-in templating for the output, I can be pretty certain that I’ll be making edits to the core plug-in files. The HTML (HyperText Markup Language) produced is rarely what I really want. My conclusion from this is that if I want to create plug-ins which will be used by sophisticated developers, then they need to be very, very flexible.

The downside to this, of course, is clear: if you can change the output, you can break it. As a result, every one of my plug-ins which creates web site output has equal potential to be accessible or inaccessible: and I can’t guarantee the results. Additionally, the core content of the site can only be as accessible as the theme surrounding it — so even if the plug-in is configured with my defaults, that doesn’t guarantee any particular level of accessibility.

I’ve had to accept that. But it does mean that I’m constantly seeing implementations of my plug-ins which, while well-done in general principle, just don’t meet my ultimate wishes for accessibility.

But I wouldn’t turn back. I’d like very much to be able to enforce accessibility; but realistically, I can’t do it. There are too many factors.

My User’s Guide to My Calendar includes a short section on the principles of Accessibility; hopefully, a few people will gain from that fact. The fact is that accessibility requires education: you can’t force accessibility on somebody by providing accessible software unless you also take total control over the look, feel, and function of that software, and that’s not the way the web works. With education, you can help move people towards making their own decision to support accessibility in how they customize their software; so that’s what I’m hoping for.

So, what does it mean to write an accessible plug-in for WordPress? I can’t control the administrative interface entirely; because the fundamental interface is the WordPress core, and I can’t just evade that. I can’t control the output, in either structure or design; and even if I could control what exists within the parameters of the plug-in’s output, I can’t control what surrounds it.

So an accessible plug-in is just a plug-in which is able to used accessibly; a plug-in which doesn’t actually implement a specific lack of accessibility. Somehow, that’s a little depressing, but you take what you can get.

The overall lesson to take from this is that no plug-in is actually going to give you an accessible web site. But hopefully, it’ll give the possibility of an accessible web site.