Tags: code

57

sparkline

Updating email addresses with Mailchimp’s API

I’ve been using Mailchimp for years now to send out a weekly newsletter from The Session. But I never visit the Mailchimp website. Instead, I use the API to create a campaign each week, and then send it out. I also use the API whenever a member of The Session updates their email preferences (or changes their details).

I got an email from Mailchimp that their old API was being deprecated and I’d need to update to their more recent one. The code I was using had been happily running for about seven years, but now I’d have to change it.

Luckily, Drew has written a really handy Mailchimp API wrapper for PHP, the language that The Session’s codebase is in. Thanks, Drew! I downloaded that wrapper and updated my code accordingly.

Everything went pretty smoothly. I was able to create campaigns, send campaigns, add new subscribers, and delete subscribers. But I ran into an issue when I wanted to update someone’s email address (on The Session, you can edit your details at any time, including your email address).

Here’s the set up:

use \DrewM\MailChimp\MailChimp;
$MailChimp = new MailChimp('abc123abc123abc123abc123abc123-us1');
$list_id = 'b1234346';
$subscriber_hash = $MailChimp -> subscriberHash('currentemail@example.com');
$endpoint = 'lists/'.$listID.'/members/'.$subscriber_hash;

Now to update details, according to the API, I can use the patch method on that endpoint:

$MailChimp -> patch($endpoint, [
    'email_address' => 'newemail@example.com'
]);

But that doesn’t work. Mailchimp effectively treats email addresses as unique IDs for subscribers. So the only way to change someone’s email address appears to be to delete them, and then subscribe them fresh with the new email address:

$MailChimp -> delete($endpoint);
$newendpoint = 'lists/'.$listID.'/members';
$MailChimp -> post($newendpoint, [
    'email_address' => 'newemail@example.com',
    'status' => 'subscribed'
]);

That’s somewhat annoying, as the previous version of the API allowed email addresses to be updated, but this workaround isn’t too arduous.

Anyway, I figured it share this just in case it was useful for anyone else migrating to the newer API.

Update: Belay that. Turns out that you can update email addresses, but you have to be sure to include the status value:

$MailChimp -> patch($endpoint, [
    'email_address' => 'newemail@example.com',
    'status' => 'subscribed'
]);

Okay, that’s a lot more straightforward. Ignore everything I said.

Going Offline—the talk of the book

I gave a new talk at An Event Apart in Seattle yesterday morning. The talk was called Going Offline, which the eagle-eyed amongst you will recognise as the title of my most recent book, all about service workers.

I was quite nervous about this talk. It’s very different from my usual fare. Usually I have some big sweeping arc of history, and lots of pretentious ideas joined together into some kind of narrative arc. But this talk needed to be more straightforward and practical. I wasn’t sure how well I would manage that brief.

I knew from pretty early on that I was going to show—and explain—some code examples. Those were the parts I sweated over the most. I knew I’d be presenting to a mixed audience of designers, developers, and other web professionals. I couldn’t assume too much existing knowledge. At the same time, I didn’t want to teach anyone to such eggs.

In the end, there was an overarching meta-theme to talk, which was this: logic is more important than code. In other words, figuring out what you’re trying to accomplish (and describing it clearly) is more important than typing curly braces and semi-colons. Programming is an act of translation. Before you can translate something, you need to be able to articulate it clearly in your own language first. By emphasising that point, I hoped to make the code less overwhelming to people unfamilar with it.

I had tested the talk with some of my Clearleft colleagues, and they gave me great feedback. But I never know until I’ve actually given a talk in front of a real conference audience whether the talk is any good or not. Now that I’ve given the talk, and received more feedback, I think I can confidentally say that it’s pretty damn good.

My goal was to explain some fairly gnarly concepts—let’s face it: service workers are downright weird, and not the easiest thing to get your head around—and to leave the audience with two feelings:

  1. This is exciting, and
  2. This is something I can do today.

I deliberately left time for questions, bribing people with free copies of my book. I got some great questions, and I may incorporate some of them into future versions of this talk (conference organisers, if this sounds like the kind of talk you’d like at your event, please get in touch). Some of the points brought up in the questions were:

  • Is there some kind of wizard for creating a typical service worker script for any site? I didn’t have a direct answer to this, but I have attempted to make a minimal viable service worker that could be used for just about any site. Mostly I encouraged the questioner to roll their sleeves up and try writing a bespoke script. I also mentioned the Workbox library, but I gave my opinion that if you’re going to spend the time to learn the library, you may as well spend the time to learn the underlying language.
  • What are some state-of-the-art progressive web apps for offline user experiences? Ooh, this one kind of stumped me. I mean, the obvious poster children for progressive webs apps are things like Twitter, Instagram, and Pinterest. They’re all great but the offline experience is somewhat limited. To be honest, I think there’s more potential for great offline experiences by publishers. I especially love the pattern on personal sites like Una’s and Sara’s where people can choose to save articles offline to read later—like a bespoke Instapaper or Pocket. I’d love so see that pattern adopted by some big publications. I particularly like that gives so much more control directly to the end user. Instead of trying to guess what kind of offline experience they want, we give them the tools to craft their own.
  • Do caches get cleaned up automatically? Great question! And the answer is mostly no—although browsers do have their own heuristics about how much space you get to play with. There’s a whole chapter in my book about being a good citizen and cleaning up your caches, but I didn’t include that in the talk because it isn’t exactly exciting: “Hey everyone! Now we’re going to do some housekeeping—yay!”
  • Isn’t there potential for abuse here? This is related to the previous question, and it’s another great question to ask of any technology. In short, yes. Bad actors could use service workers to fill up caches uneccesarily. I’ve written about back door service workers too, although the real problem there is with iframes rather than service workers—iframes and cookies are technologies that are already being abused by bad actors, and we’re going to see more and more interventions by ethical browser makers (like Mozilla) to clamp down on those technologies …just as browsers had to clamp down on the abuse of pop-up windows in the early days of JavaScript. The cache API could become a tragedy of the commons. I liken the situation to regulation: we should self-regulate, but if we prove ourselves incapable of that, then outside regulation (by browsers) will be imposed upon us.
  • What kind of things are in the future for service workers? Excellent question! If you think about it, a service worker is kind of a conduit that gives you access to different APIs: the Cache API and the Fetch API being the main ones now. A service worker is like an airport and the APIs are like the airlines. There are other APIs that you can access through service workers. Notifications are available now on desktop and on Android, and they’ll be coming to iOS soon. Background Sync is another powerful API accessed through service workers that will get more and more browser support over time. The great thing is that you can start using these APIs today even if they aren’t universally supported. Then, over time, more and more of your users will benefit from those enhancements.

If you attended the talk and want to learn more about about service workers, there’s my book (obvs), but I’ve also written lots of blog posts about service workers and I’ve linked to lots of resources too.

Finally, here’s a list of links to all the books, sites, and articles I referenced in my talk…

Books

Sites

Progressive Web Apps

A tiny lesson in query selection

We have a saying at Clearleft:

Everything is a tiny lesson.

I bet you learn something new every day, even if it’s something small. These small tips and techniques can easily get lost. They seem almost not worth sharing. But it’s the small stuff that takes the least effort to share, and often provides the most reward for someone else out there. Take for example, this great tip for getting assets out of Sketch that Cassie shared with me.

Cassie was working on a piece of JavaScript yesterday when we spotted a tiny lesson that tripped up both of us. The script was a fairly straightforward piece of DOM scripting. As a general rule, we do a sort of feature detection near the start of the script. Let’s say you’re using querySelector to get a reference to an element in the DOM:

var someElement = document.querySelector('.someClass');

Before going any further, check to make sure that the reference isn’t falsey (in other words, make sure that DOM node actually exists):

if (!someElement) return;

That will exit the script if there’s no element with a class of someClass on the page.

The situation that tripped us up was like this:

var myLinks = document.querySelectorAll('a.someClass');

if (!myLinks) return;

That should exit the script if there are no A elements with a class of someClass, right?

As it turns out, querySelectorAll is subtly different to querySelector. If you give querySelector a reference to non-existent element, it will return a value of null (I think). But querySelectorAll always returns an array (well, technically it’s a NodeList but same difference mostly). So if the selector you pass to querySelectorAll doesn’t match anything, it still returns an array, but the array is empty. That means instead of just testing for its existence, you need to test that it’s not empty by checking its length property:

if (!myLinks.length) return;

That’s a tiny lesson.

Code print

You know what I like? Print stylesheets!

I mean, I’m not a huge fan of trying to get the damn things to work consistently—thanks, browsers—but I love the fact that they exist (athough I’ve come across a worrying number of web developers who weren’t aware of their existence). Print stylesheets are one more example of the assumption-puncturing nature of the web: don’t assume that everyone will be reading your content on a screen. News articles, blog posts, recipes, lyrics …there are many situations where a well-considered print stylesheet can make all the difference to the overall experience.

You know what I don’t like? QR codes!

It’s not because they’re ugly, or because they’ve been over-used by the advertising industry in completely inapropriate ways. No, I don’t like QR codes because they aren’t an open standard. Still, I must grudgingly admit that they’re a convenient way of providing a shortcut to a URL (albeit a completely opaque one—you never know if it’s actually going to take you to the URL it promises or to a Rick Astley video). And now that the parsing of QR codes is built into iOS without the need for any additional application, the barrier to usage is lower than ever.

So much as I might grit my teeth, QR codes and print stylesheets make for good bedfellows.

I picked up a handy tip from a Smashing Magazine article about print stylesheets a few years back. You can the combination of a @media print and generated content to provide a QR code for the URL of the page being printed out. Google’s Chart API provides a really handy shortcut for generating QR codes:

https://chart.googleapis.com/chart?cht=qr&chs=150x150&chl=http://example.com

Except that there’s no telling how long that will continue to work. Google being Google, they’ve deprecated the simple image chart API in favour of the over-engineered JavaScript alternative. So just as I recently had to migrate all my maps over to Leaflet when Google changed their Maps API from under the feet of developers, the clock is ticking on when I’ll have to find an alternative to the Image Charts API.

For now, I’ve got the QR code generation happening on The Session for individual discussions, events, recordings, sessions, and tunes. For the tunes, there’s also a separate URL for each setting of a tune, specifically for printing out. I’ve added a QR code there too.

Experimenting with print stylesheets and QR codes.

I’ve been thinking about another potential use for QR codes. I’m preparing a new talk for An Event Apart Seattle. The talk is going to be quite practical—for a change—and I’m going to be encouraging people to visit some URLs. It might be fun to include the biggest possible QR code on a slide.

I’d better generate the images before Google shuts down that API.

The trimCache function in Going Offline

Paul Yabsley wrote to let me know about an error in Going Offline. It’s rather embarrassing because it’s code that I’m using in the service worker for adactio.com but for some reason I messed it up in the book.

It’s the trimCache function in Chapter 7: Tidying Up. That’s the reusable piece of code that recursively reduces the number of items in a specified cache (cacheName) to a specified amount (maxItems). On page 95 and 96 I describe the process of creating the function which, in the book, ends up like this:

 function trimCache(cacheName, maxItems) {
   cacheName.open( cache => {
     cache.keys()
     .then( items => {
       if (items.length > maxItems) {
         cache.delete(items[0])
         .then(
           trimCache(cacheName, maxItems)
         ); // end delete then
       } // end if
     }); // end keys then
   }); // end open
 } // end function

See the problem? It’s right there at the start when I try to open the cache like this:

cacheName.open( cache => {

That won’t work. The open method only works on the caches object—I should be passing the name of the cache into the caches.open method. So the code should look like this:

caches.open( cacheName )
.then( cache => {

Everything else remains the same. The corrected trimCache function is here:

function trimCache(cacheName, maxItems) {
  caches.open(cacheName)
  .then( cache => {
    cache.keys()
    .then(items => {
      if (items.length > maxItems) {
        cache.delete(items[0])
        .then(
          trimCache(cacheName, maxItems)
        ); // end delete then
      } // end if
    }); // end keys then
  }); // end open then
} // end function

Sorry about that! I must’ve had some kind of brainfart when I was writing (and describing) that one line of code.

You may want to deface your copy of Going Offline by taking a pen to that code example. Normally I consider the practice of writing in books to be barbarism, but in this case …go for it.

Why Design Systems Fail by Una Kravets

I’m at An Event Apart Boston where Una is about to talk about design systems, following on from Yesenia’s excellent design systems talk. I’m going to attempt to liveblog it…

Una works at the Bustle Digital Group, which publishes a lot of different properties. She used to work at Watson, at Bluemix and at Digital Ocean. They all have something in common (other than having blue in their logos). They all had design systems that failed.

Design systems are so hot right now. They allow us think in a componentised way, and grow quickly. There are plenty of examples out there, like Polaris from Shopify, the Lightning design sytem from Salesforce, Garden from Zendesk, Gov.uk, and Code For America. Check out Anna’s excellent styleguides.io for more examples.

What exactly is a design system?

It’s a broad term. It can be a styleguide or visual pattern library. It can be design tooling (like a Sketch file). It can be a component library. It can be documentation of design or development usage. It can be voice and tone guidelines.

Styleguides

When Una was in College, she had a print rebranding job—letterheads, stationary, etc. She also had to provide design guidelines. She put this design guide on the web. It had colours, heading levels, type, logo treatments, and so on. It wasn’t for an application, but it was a design system.

Design tooling

Primer by Github is a good example of this. You can download pre-made icons, colours, etc.

Component library

This is where you get the code. Una worked on BUI at Digital Ocean, which described the interaction states of each components and how to customise interactions with JavaScript.

Code usage guidelines

AirBnB has a really good example of this. It’s a consistent code style. You can even include it in your build step with eslint-config-airbnb and stylelint-config-airbnb.

Design usage documentation

Carbon by IBM does a great job of this. It describes the criteria for deciding when to use a pattern. It’s driven by user experience considerations. They also have general guidelines on loading in components—empty states, etc. And they include animation guidelines (separately from Carbon), built on the history of IBM’s magnetic tape machines and typewriters.

Voice and tone guidelines

Of course Mailchimp is the classic example here. They break up voice and tone. Voice is not just what the company is, but what the company is not:

  • Fun but not silly,
  • Confident but not cocky,
  • Smart but not stodgy,
  • and so on.

Voiceandtone.com describes the user’s feelings at different points and how to communicate with them. There are guidelines for app users, and guidelines for readers of the company newsletter, and guidelines for readers of the blog, and so on. They even have examples of when things go wrong. The guidelines provide tips on how to help people effectively.

Why do design systems fail?

Una now asks who in the room has ever started a diet. And who has ever finished a diet? (A lot of hands go down).

Nobody uses it

At Digital Ocean, there was a design system called Buoy version 1. Una helped build a design system called Float. There was also a BUI version 2. Buoy was for product, Float was for the marketing site. Classic example of 927. Nobody was using them.

Una checked the CSS of the final output and the design system code only accounted for 28% of the codebase. Most of the CSS was over-riding the CSS in the design system.

Happy design systems scale good standards, unify component styles and code and reduce code cruft. Why were people adding on instead of using the existing sytem? Because everyone was being judged on different metrics. Some teams were judged on shipping features rather than producing clean code. So the advantages of a happy design systems don’t apply to them.

Investment

It’s like going to the gym. Small incremental changes make a big difference over the long term. If you just work out for three months and then stop, you’ll lose all your progress. It’s like that with design systems. They have to stay in sync with the live site. If you don’t keep it up to date, people just won’t use it.

It’s really important to have a solid core. Accessibility needs to be built in from the start. And the design system needs ownership and dedicated commitment. That has to come from the organisation.

You have to start somewhere.

Communication

Communication is multidimensional; it’s not one-way. The design system owner (or team) needs to act as a bridge between designers and developers. Nobody likes to be told what to do. People need to be involved, and feel like their needs are being addressed. Make people feel like they have control over the process …even if they don’t; it’s like perceived performance—this is perceived involvement.

Ask. Listen. Make your users feel heard. Incorporate feedback.

Buy-in

Good communication is important for getting buy-in from the people who will use the design system. You also need buy-in from the product owners.

Showing is more powerful than telling. Hackathans are like candy to a budding design system—a chance to demonstrate the benefits of a design system (and get feedback). After a hackathon at Digital Ocean, everyone was talking about the design system. Weeks afterwards, one of the developers replaced Bootstrap with BUI, removing 20,000 lines of code! After seeing the impact of a design system, the developers will tell their co-workers all about it.

Solid architecture

You need to build with composability and change in mind. Primer, by Github, has a core package, and then add-ons for, say, marketing or product. That separation of concerns is great. BUI used a similar module-based approach: a core codebase, separate from iconography and grid.

Semantic versioning is another important part of having a solid architecture for your design system. You want to be able to push out minor updates without worrying about breaking changes.

Major.Minor.Patch

Use the same convention in your design files, like Sketch.

What about tech stack choice? Every company has different needs, but one thing Una recommends is: don’t wait to namespace! All your components should have some kind of prefix in the class names so they don’t clash with existing CSS.

Una mentions Solid by Buzzfeed, which I personally think is dreadful (count the number of !important declarations—you can call it “immutable” all you want).

AtlasKit by Atlassian goes all in on React. They’re trying to integrate Sketch into it, but design tooling isn’t solved yet (AirBnB are working on this too). We’re still trying to figure out how to merge the worlds of design and code.

Reduce Friction

This is what it’s all about. Using the design system has to be the path of least resistance. If the new design system is harder to use than what people are already doing, they won’t use it.

Provide hooks and tools for the people who will be using the design system. That might be mixins in Sass or it might be a script on a CDN that people can just link to.

Start early, update often. Design systems can be built retrospectively but it’s easier to do it when a new product is being built.

Bugs and cruft always increase over time. You need a mechanism in place to keep on top of it. Not just technical bugs, but visual inconsistencies.

So the five pillars of ensuring a successful design system are:

  1. Investment
  2. Communication
  3. Buy-in
  4. Solid architecture
  5. Reduce friction

When you’re starting, begin with a goal:

We are building a design system because…

Then review what you’ve already got (your existing codebase). For example, if the goal of having a design system is to increase page performance, use Web Page Test to measure how the current site is performing. If the goal is to reduce accessibility problems, use webaim.org to measure the accessibility of your current site (see also: pa11y). If the goal is to reduce the amount of CSS in your codebase, use cssstats.com to test how your current site is doing. Now that you’ve got stats, use them to get buy-in. You can also start by doing an interface inventory. Print out pages and cut them up.

Once you’ve got buy-in and commitment (in writing), then you can make technical decisions.

You can start with your atomic elements. Buttons are like the “Hello world!” of design systems. You’ve colours, type, and different states.

Then you can compose elements by putting the base elements together.

Do you include layout in the system? That’s a challenge, and it depends on your team. If you do include layout, to what extent?

Regardless of layout, you still need to think about space: the space between base elements within a component.

Bake in accessibility: every hover state should have an equal (not opposite) focus state.

Think about states, like loading states.

Then you can start documenting. Then inform the users of the system. Carbon has a dashboard showing which components are new, which components are deprecated, and which components are being updated.

Keep consistent communication. Design and dev communication has to happen. Continuous iteration, support and communication are the most important factors in the success of a design system. Code is only 10% of a sytem.

Also, don’t feel like you need to copy other design systems out there. Your needs are probably very different. As Diana says, comparing your design system to the polished public ones is like comparing your life to someone’s Instagram account. To that end, Una says something potentially contraversial:

You might not need a design sytem.

If you’re the only one at your organisation that cares about the benefits of a design system, you won’t get buy-in, and if you don’t get buy-in, the design system will fail. Maybe there’s something more appropriate for your team? After all, not everyone needs to go to the gym to get fit. There are alternatives.

Find what works for you and keep at it.

The audience for Going Offline

My new book, Going Offline, starts with no assumption of JavaScript knowledge, but by the end of the book the reader is armed with enough code to make any website work offline.

I didn’t want to overwhelm the reader with lots of code up front, so I’ve tried to dole it out in manageable chunks. The amount of code ramps up a little bit in each chapter until it peaks in chapter five. After that, it ramps down a bit with each subsequent chapter.

This tweet perfectly encapsulates the audience I had in mind for the book:

Some people have received advance copies of the PDF, and I’m very happy with the feedback I’m getting.

Honestly, that is so, so gratifying to hear!

Words cannot express how delighted I am with Sara’s reaction:

She’s walking the walk too:

That gives me a warm fuzzy glow!

If you’ve been nervous about service workers, but you’ve always wanted to turn your site into a progressive web app, you should get a copy of this book.

Minimal viable service worker

I really, really like service workers. They’re one of those technologies that have such clear benefits to users that it seems like a no-brainer to add a service worker to just about any website.

The thing is, every website is different. So the service worker strategy for every website needs to be different too.

Still, I was wondering if it would be possible to create a service worker script that would work for most websites. Here’s the script I came up with.

The logic works like this:

  • If there’s a request for an HTML page, fetch it from the network and store a copy in a cache (but if the network request fails, try looking in the cache instead).
  • For any other files, look for a copy in the cache first but meanwhile fetch a fresh version from the network to update the cache (and if there’s no existing version in the cache, fetch the file from the network and store a copy of it in the cache).

So HTML files are served network-first, while all other files are served cache-first, but in both cases a fresh copy is always put in the cache. The idea is that HTML content will always be fresh (unless there’s a problem with the network), while all other content—images, style sheets, scripts—might be slightly stale, but get refreshed with every request.

My original attempt was riddled with errors. Jake came to my rescue and we revised the script into something that actually worked. In the process, my misunderstanding of how await works led Jake to write a great blog post on await vs return vs return await.

I got there in the end and the script seems solid enough. It’s a fairly simplistic strategy that could work for quite a few sites, but it has some issues…

Service workers don’t perform any automatic cleanup of caches—that’s up to you to do (usually during the activate event). This script doesn’t do any cleanup so the cache might grow and grow and grow. For that reason, I think the script is best suited for fairly small sites.

The strategy also assumes that a file will either be fetched from the network or the cache. There’s no contingency for when both attempts fail. So there’s no fallback offline page, for example.

I decided to test it in the wild, but I expanded it slightly to fix the fallback issue. The version on the Ampersand 2018 website includes a worst-case-scenario option to show a custom offline page that has been pre-cached. (By the way, if you haven’t got a ticket for Ampersand yet, get a ticket now—it’s going to be superb day of web typography nerdery.)

Anyway, this fairly basic script seems to be delivering some good performance improvements. If you’ve got a site that you think would benefit from this network/caching strategy, and it’s served over HTTPS, then:

  1. Feel free to download the script or copy and paste it into a file called serviceworker.js,
  2. Put that file in the root directory of your website,
  3. Add this in a script element at the bottom of your HTML pages:

if (navigator.serviceWorker && !navigator.serviceWorker.controller) { navigator.serviceWorker.register('/serviceworker.js'); }

You can also use the script as a starting point. You might find issues specific to your particular website. That’s okay—you can tweak and adjust the script to suit your needs.

If this minimal service worker script proves in any way useful to you, thank Jake.

Putting on a conference

It’s been a few weeks now since Patterns Day and I’m still buzzing from it. I might be biased, but I think it was a great success all ‘round—for attendees, for speakers, and for us at Clearleft organising the event.

I first had the idea for Patterns Day quite a while back. To turn the idea into reality meant running some numbers. Patterns Day wouldn’t have been possible without Alis. She did all the logistical work—the hard stuff—which freed me up to concentrate on the line-up. I started to think about who I could invite to speak, and at the same time, started looking for a venue.

I knew from the start that I wanted it to be one-day single-track conference in Brighton, much like Responsive Day Out. I knew I wouldn’t be able to use the Corn Exchange again—there’s extensive rebuilding going on there this year. I put together a shortlist of Brighton venues and Alis investigated their capacities and costs, but to be honest, I knew that I wanted to have it in the Duke Of York’s. I love that place, and I knew from attending FFconf that it makes for an excellent conference venue.

The seating capacity of the Duke Of York’s is quite a bit less than the Corn Exchange, so I knew the ticket price would have to be higher than that of Responsive Day Out. The Duke Of York’s isn’t cheap to rent for the day either (but worth every penny).

To calculate the ticket price, I had to figure out the overall costs:

  • Venue hire,
  • A/V hire,
  • Printing costs (for name badges, or in this case, stickers),
  • Payment provider commission—we use Stripe through the excellent Ti.to,
  • Speaker’s travel,
  • Speaker’s accommodation,
  • Speaker’s dinner the evening before the event,
  • Speaker’s payment.

Some conference organisers think they can skimp on that last part. Those conference organisers are wrong. A conference is nothing without its speakers. They are literally the reason why people buy tickets.

Because the speakers make or break a conference, there’s a real temptation to play it safe and only book people who are veterans. But then you’re missing out on a chance to boost someone when they’re just starting out with public speaking. I remember taking a chance on Alla a few years back for Responsive Day Out 3—she had never given a conference talk before. She, of course, gave a superb talk. Now she’s speaking at events all over the world, and I have to admit, it gives me a warm glow inside. When it came time for Patterns Day, Alla had migrated into the “safe bet” category—I knew she’d deliver the perfect closing keynote.

I understand why conference organisers feel like they need to play it safe. From their perspective, they’re already taking on a lot of risk in putting on a conference in the first place. It’s easy to think of yourself as being in a position of vulnerability—”If I don’t sell enough tickets, I’m screwed!” But I think it’s important to realise that you’re also in a position of power, whether you like it or not. If you’re in charge of putting together the line-up of a conference, that’s a big responsibility, not just to the attendees on the day, but to the community as a whole. It’s like that quote by Eliel Saarinen:

Always design a thing by considering it in its next larger context. A chair in a room, a room in a house, a house in an environment, an environment in a city plan.

Part of that responsibility to the wider community is representation. That’s why I fundamentally disagree with ppk when he says:

The other view would be that there should be 50% woman speakers. Although that sounds great I personally never believed in this argument. It’s based on the general population instead of the population of web developers, and if we’d extend that argument to its logical conclusion then 99.9% of the web development conference speakers should know nothing about web development, since that’s the rough ratio in the general population.

That makes it sound like a conference’s job is to represent the status quo. By that logic, the line-up should include plenty of bad speakers—after all, the majority of web developers aren’t necessarily good speakers. But of course that’s not how conferences work. They don’t represent typical ideas—quite the opposite. What’s the point of having an event that simply reinforces the general consensus? This isn’t Harrison Bergeron. You want a line-up that’s exceptional.

I don’t think conference organisers can shirk this issue and say “It’s out of my hands; I’m just reflecting the way things are.” The whole point of having a conference in the first place is to trigger some kind of change. If you’re not happy with the current make-up of the web community (and I most definitely am not), then a conference is the perfect opportunity to try to demonstrate an alternative. We do it with the subject matter of the talks—”Our code/process/tooling doesn’t have to be this way!”—and I think we should also apply that to the wider context: “Our culture doesn’t have to be this way!”

Passing up that chance isn’t just a missed opportunity, I think it’s also an abdication of responsibility. Believe me, I know that organising a conference is a lot of work, but that’s not a reason to cop out. On the contrary, it’s all the more reason to step up to the plate and try your damnedest to make a difference. Otherwise, why even have a conference?

Whenever the issue of diversity at conferences comes up, there is inevitably someone who says “All I care about is having the best speakers.” But if that were true, shouldn’t your conference (and every other conference) have exactly the same line-up every year?

The truth is that there are all sorts of factors that play into the choice of speakers. I think representation should be a factor, but that’s all it is—one factor of many. Is the subject matter relevant? That’s a factor. Do we already have someone on the line-up covering similar subject matter? That’s a factor. How much will it cost to get this speaker? That’s a factor. Is the speaker travelling from very far away? That’s a factor.

In the case of Patterns Day, I had to factor in the range of topics. I wanted a mixture of big-picture talks as well as hands-on nitty-gritty case studies. I also didn’t want it to be too developer-focused or too design-focused. I was aiming for a good mix of both.

In the end, I must admit that I am guilty of doing exactly what I’ve been railing against. I played it safe. I put together a line-up of speakers that I wanted to see, and that I knew with absolute certainty would deliver great presentations. There were plenty of potential issues for me to get stressed about in the run-up to the event, but the quality of the talks wasn’t one of them. On the one hand, I wish I had taken more chances with the line-up, but honestly, if I could do it over again, I wouldn’t change a thing.

Because I was trying to keep the ticket price as low as possible—and the venue hire was already a significant cost—I set myself the constraint of only having speakers from within the UK (Jina was the exception—she was going to come anyway as an attendee, so of course I asked her to speak). Knowing that the speaker’s travel costs would be low, I could plug the numbers into an algebraic formula for figuring out the ticket price:

costs ÷ seats = price

Add up all the costs and divide that total by the number of available seats to get the minimum ticket price.

In practice, you probably don’t want to have to sell absolutely every single ticket just to break even, so you set the price for a sales figure lower than 100%—maybe 80%, or 50% if you’re out to make a tidy profit (although if you’re out to make a tidy profit, I don’t think conferences are the right business to be in—ask any conference organiser).

Some conferences factor in money for sponsorship to make the event happen. I prefer to have sponsors literally sponsoring additions to the conference. In the case of Patterns Day, the coffee and pastries were sponsored by Deliveroo, and the videos were sponsored by Amazon. But sponsorship didn’t affect the pricing formula.

The Duke Of York’s has around 280 seats. I factored in about 30 seats for speakers, Clearlefties, and other staff. That left 250 seats available for attendees. But that’s not the number I plugged into the pricing formula. Instead, I chose to put 210 tickets on sale and figured out the ticket price accordingly.

What happened to the remaining 40 seats? The majority of them went to Codebar students and organisers. So if you bought a ticket for Patterns Day, you directly subsidised the opportunity for people under-represented in technology to attend. Thank you.

Speaking personally, I found that having the Codebar crew in attendance really made my day. They’re my heroes, and it meant the world to me that they were able to be there.

Zara, Alice, and Amber Patterns Day Anwen, Zara, Alice, Dot, and Amber Eden, Zara, Alice, and Chloe

Month maps

One of the topics I enjoy discussing at Indie Web Camps is how we can use design to display activity over time on personal websites. That’s how I ended up with sparklines on my site—it was the a direct result of a discussion at Indie Web Camp Nuremberg a year ago:

During the discussion at Indie Web Camp, we started looking at how silos design their profile pages to see what we could learn from them. Looking at my Twitter profile, my Instagram profile, my Untappd profile, or just about any other profile, it’s a mixture of bio and stream, with the addition of stats showing activity on the site—signs of life.

Perhaps the most interesting visual example of my activity over time is on my Github profile. Halfway down the page there’s a calendar heatmap that uses colour to indicate the amount of activity. What I find interesting is that it’s using two axes of time over a year: days of the month across the X axis and days of the week down the Y axis.

I wanted to try something similar, but showing activity by time of day down the Y axis. A month of activity feels like the right range to display, so I set about adding a calendar heatmap to monthly archives. I already had the data I needed—timestamps of posts. That’s what I was already using to display sparklines. I wrote some code to loop over those timestamps and organise them by day and by hour. Then I spit out a table with days for the columns and clumps of hours for the rows.

Calendar heatmap on Dribbble

I’m using colour (well, different shades of grey) to indicate the relative amounts of activity, but I decided to use size as well. So it’s also a bubble chart.

It doesn’t work very elegantly on small screens: the table is clipped horizontally and can be swiped left and right. Ideally the visualisation itself would change to accommodate smaller screens.

Still, I kind of like the end result. Here’s last month’s activity on my site. Here’s the same time period ten years ago. I’ve also added month heatmaps to the monthly archives for my journal, links, and notes. They’re kind of like an expanded view of the sparklines that are shown with each month.

From one year ago, here’s the daily distribution of

And then here’s the the daily distribution of everything in that month all together.

I realise that the data being displayed is probably only of interest to me, but then, that’s one of the perks of having your own website—you can do whatever you feel like.

Open source

Building and maintaining an open-source project is hard work. That observation is about as insightful as noting the religious affiliation of the pope or the scatological habits of woodland bears.

Nolan Lawson wrote a lengthy post describing what it feels like to be an open-source maintainer.

Outside your door stands a line of a few hundred people. They are patiently waiting for you to answer their questions, complaints, pull requests, and feature requests.

You want to help all of them, but for now you’re putting it off. Maybe you had a hard day at work, or you’re tired, or you’re just trying to enjoy a weekend with your family and friends.

But if you go to github.com/notifications, there’s a constant reminder of how many people are waiting

Most of the comments on the post are from people saying “Yup, I hear ya!”

Jan wrote a follow-up post called Sustainable Open Source: The Maintainers Perspective or: How I Learned to Stop Caring and Love Open Source:

Just because there are people with problems in front of your door, that doesn’t mean they are your problems. You can choose to make them yours, but you want to be very careful about what to care about.

There’s also help at hand in the shape of Open Source Guides created by Nadia Eghbal:

A collection of resources for individuals, communities, and companies who want to learn how to run and contribute to an open source project.

I’m sure Mark can relate to all of the tales of toil that come with being an open-source project maintainer. He’s been working flat-out on Fractal, sometimes at work, but often at home too.

Fractal isn’t really a Clearleft project, at least not in the same way that something like Silverback or UX London is. We’re sponsoring Fractal as much as we can, but an open-source project doesn’t really belong to anyone; everyone is free to fork it and take it. But I still want to make sure that Mark and Danielle have time at work to contribute to Fractal. It’s hard to balance that with the bill-paying client work though.

I invited Remy around to chat with them last week. It was really valuable. Mind you, Remy was echoing many of the same observations made in Nolan’s post about how draining this can be.

So nobody here is under any illusions that this open-source lark is to be entered into lightly. It can be a gruelling exercise. But then it can also be very, very rewarding. One kind word from somebody using your software can make your day. I was genuinely pleased as punch when Danish agency Shift sent Mark a gift to thank him for all his hard work on Fractal.

People can be pretty darn great (which I guess is an underlying principle of open source).

Code (p)reviews

I’m not a big fan of job titles. I’ve always had trouble defining what I do as a noun—I much prefer verbs (“I make websites” sounds fine, but “website maker” sounds kind of weird).

Mind you, the real issue is not finding the right words to describe what I do, but rather figuring out just what the heck it is that I actually do in the first place.

According to the Clearleft website, I’m a technical director. That doesn’t really say anything about what I do. To be honest, I tend to describe my work these days in terms of what I don’t do: I don’t tend to write a lot of HTML, CSS, and JavaScript on client projects (although I keep my hand in with internal projects, and of course, personal projects).

Instead, I try to make sure that the people doing the actual coding—Mark, Graham, and Danielle—are happy and have everything they need to get on with their work. From outside, it might look like my role is managerial, but I see it as the complete opposite. They’re not in service to me; I’m in service to them. If they’re not happy, I’m not doing my job.

There’s another aspect to this role of technical director, and it’s similar to the role of a creative director. Just as a creative director is responsible for the overall direction and quality of designs being produced, I have an oversight over the quality of front-end output. I don’t want to be a bottleneck in the process though, and to be honest, most of the time I don’t do much checking on the details of what’s being produced because I completely trust Mark, Graham, and Danielle to produce top quality code.

But I feel I should be doing more. Again, it’s not that I want to be a bottleneck where everything needs my approval before it gets delivered, but I hope that I could help improve everyone’s output.

Now the obvious way to do this is with code reviews. I do it a bit, but not nearly as much as I should. And even when I do, I always feel it’s a bit late to be spotting any issues. After all, the code has already been written. Also, who am I to try to review the code produced by people who are demonstrably better at coding than I am?

Instead I think it will be more useful for me to stick my oar in before a line of code has been written; to sit down with someone and talk through how they’re going to approach solving a particular problem, creating a particular pattern, or implementing a particular user story.

I suppose it’s really not that different to rubber ducking. Having someone to talk out loud with about potential solutions can be really valuable in my experience.

So I’m going to start doing more code previews. I think it will also incentivise me to do more code reviews—being involved in the initial discussion of a solution means I’m going to want to see the final result.

But I don’t think this should just apply to front-end code. I’d also like to exercise this role as technical director with the designers on a project.

All too often, decisions are made in the design phase that prove problematic in development. It usually works out okay, but it often means revisiting the designs in light of some technical considerations. I’d like to catch those issues sooner. That means sticking my nose in much earlier in the process, talking through what the designers are planning to do, and keeping an eye out for any potential issues.

So, as technical director, I won’t be giving feedback like “the colour’s not working for me” or “not sure about those type choices” (I’ll leave that to the creative director), but instead I can ask questions like “how will this work without hover?” or “what happens when the user does this?” as well as pointing out solutions that might be tricky or time-consuming to implement from a technical perspective.

What I want to avoid is the swoop’n’poop, when someone seagulls in after something has been designed or built and points out all the problems. The earlier in the process any potential issues can be spotted, the better.

And I think that’s my job.

Amber

I really enjoyed teaching in Porto last week. It was like having a week-long series of CodeBar sessions.

Whenever I’m teaching at CodeBar, I like to be paired up with people who are just starting out. There’s something about explaining the web and HTML from first principles that I really like. And people often have lots and lots of questions that I enjoy answering (if I can). At CodeBar—and at The New Digital School—I found myself saying “Great question!” multiple times. The really great questions are the ones that I respond to with “I don’t know …let’s find out!”

CodeBar is always a very rewarding experience for me. It has given me the opportunity to try teaching. And having tried it, I can now safely say that I like it. It’s also a great chance to meet people from all walks of life. It gets me out of my bubble.

I can’t remember when I was first paired up with Amber at CodeBar. It must have been sometime last year. I do remember that she had lots of great questions—at some point I found myself explaining how hexadecimal colours work.

I was impressed with Amber’s eagerness to learn. I also liked that she was making her own website. I told her about Homebrew Website Club and she started coming along to that (along with other CodeBar people like Cassie and Alice).

I’ve mentioned to multiple CodeBar students that there’s pretty much an open-door policy at Clearleft when it comes to shadowing: feel free to come along and sit with a front-end developer while they’re working on client projects. A few people have taken up the offer and enjoyed observing myself or Charlotte at work. Amber was one of those people. Again, I was very impressed with her drive. She’s got a full-time job (with sometimes-crazy hours) but she’s so determined to get into the world of web design and development that she’s willing to spend her free time visiting Clearleft to soak up the atmosphere of a design studio.

We’ve decided to turn this into something more structured. Amber and I will get together for a couple of hours once a week. She’s given me a list of some of the areas she wants to explore, and I think it’s a fine-looking list:

  • I want to gather base, structural knowledge about the web and all related aspects. Things seem to float around in a big cloud at the moment.
  • I want to adhere to best practices.
  • I want to learn more about what direction I want to go in, find a niche.
  • I’d love to opportunity to chat with the brilliant people who work at Clearleft and gain a broad range of knowledge from them.

My plan right now is to take a two-track approach: one track about the theory, and another track about the practicalities. The practicalities will be HTML, CSS, JavaScript, and related technologies. The theory will be about understanding the history of the web and its strengths and weaknesses as a medium. And I want to make sure there’s plenty of UX, research, information architecture and content strategy covered too.

Seeing as we’ll only have a couple of hours every week, this won’t be quite like the masterclass I just finished up in Porto. Instead I imagine I’ll be laying some groundwork and then pointing to topics to research. I guess it’s a kind of homework. For example, after we talked today, I set Amber this little bit of research for the next time we meet: “What is the difference between the internet and the World Wide Web?”

I’m excited to see where this will lead. I find Amber’s drive and enthusiasm very inspiring. I also feel a certain weight of responsibility—I don’t want to enter into this lightly.

I’m not really sure what to call this though. Is it mentorship? Or is it coaching? Or training? All of the above?

Whatever it is, I’m looking forward to documenting the journey. Amber will be writing about it too. She is already demonstrating a way with words.

Making Resilient Web Design work offline

I’ve written before about taking an online book offline, documenting the process behind the web version of HTML5 For Web Designers. A book is quite a static thing so it’s safe to take a fairly aggressive offline-first approach. In fact, a static unchanging book is one of the few situations that AppCache works for. Of course a service worker is better, but until AppCache is removed from browsers (and until service worker is supported across the board), I’m using both. I wouldn’t recommend that for most sites though—for most sites, use a service worker to enhance it, and avoid AppCache like the plague.

For Resilient Web Design, I took a similar approach to HTML5 For Web Designers but I knew that there was a good chance that some of the content would be getting tweaked at least for a while. So while the approach is still cache-first, I decided to keep the cache fairly fresh.

Here’s my service worker. It starts with the usual stuff: when the service worker is installed, there’s a list of static assets to cache. In this case, that list is literally everything; all the HTML, CSS, JavaScript, and images for the whole site. Again, this is a pattern that works well for a book, but wouldn’t be right for other kinds of websites.

The real heavy lifting happens with the fetch event. This is where the logic sits for what the service worker should do everytime there’s a request for a resource. I’ve documented the logic with comments:

// Look in the cache first, fall back to the network
  // CACHE
  // Did we find the file in the cache?
      // If so, fetch a fresh copy from the network in the background
      // NETWORK
          // Stash the fresh copy in the cache
  // NETWORK
  // If the file wasn't in the cache, make a network request
      // Stash a fresh copy in the cache in the background
  // OFFLINE
  // If the request is for an image, show an offline placeholder
  // If the request is for a page, show an offline message

So my order of preference is:

  1. Try the cache first,
  2. Try the network second,
  3. Fallback to a placeholder as a last resort.

Leaving aside that third part, regardless of whether the response is served straight from the cache or from the network, the cache gets a top-up. If the response is being served from the cache, there’s an additional network request made to get a fresh copy of the resource that was just served. This means that the user might be seeing a slightly stale version of a file, but they’ll get the fresher version next time round.

Again, I think this acceptable for a book where the tweaks and changes should be fairly minor, but I definitely wouldn’t want to do it on a more dynamic site where the freshness matters more.

Here’s what it usually likes like when a file is served up from the cache:

caches.match(request)
  .then( responseFromCache => {
  // Did we find the file in the cache?
  if (responseFromCache) {
      return responseFromCache;
  }

I’ve introduced an extra step where the fresher version is fetched from the network. This is where the code can look a bit confusing: the network request is happening in the background after the cached file has already been returned, but the code appears before the return statement:

caches.match(request)
  .then( responseFromCache => {
  // Did we find the file in the cache?
  if (responseFromCache) {
      // If so, fetch a fresh copy from the network in the background
      event.waitUntil(
          // NETWORK
          fetch(request)
          .then( responseFromFetch => {
              // Stash the fresh copy in the cache
              caches.open(staticCacheName)
              .then( cache => {
                  cache.put(request, responseFromFetch);
              });
          })
      );
      return responseFromCache;
  }

It’s asynchronous, see? So even though all that network code appears before the return statement, it’s pretty much guaranteed to complete after the cache response has been returned. You can verify this by putting in some console.log statements:

caches.match(request)
.then( responseFromCache => {
  if (responseFromCache) {
      event.waitUntil(
          fetch(request)
          .then( responseFromFetch => {
              console.log('Got a response from the network.');
              caches.open(staticCacheName)
              .then( cache => {
                  cache.put(request, responseFromFetch);
              });
          })
      );
      console.log('Got a response from the cache.');
      return responseFromCache;
  }

Those log statements will appear in this order:

Got a response from the cache.
Got a response from the network.

That’s the opposite order in which they appear in the code. Everything inside the event.waitUntil part is asynchronous.

Here’s the catch: this kind of asynchronous waitUntil hasn’t landed in all the browsers yet. The code I’ve written will fail.

But never fear! Jake has written a polyfill. All I need to do is include that at the start of my serviceworker.js file and I’m good to go:

// Import Jake's polyfill for async waitUntil
importScripts('/js/async-waituntil.js');

I’m also using it when a file isn’t found in the cache, and is returned from the network instead. Here’s what the usual network code looks like:

fetch(request)
  .then( responseFromFetch => {
    return responseFromFetch;
  })

I want to also store that response in the cache, but I want to do it asynchronously—I don’t care how long it takes to put the file in the cache as long as the user gets the response straight away.

Technically, I’m not putting the response in the cache; I’m putting a copy of the response in the cache (it’s a stream, so I need to clone it if I want to do more than one thing with it).

fetch(request)
  .then( responseFromFetch => {
    // Stash a fresh copy in the cache in the background
    let responseCopy = responseFromFetch.clone();
    event.waitUntil(
      caches.open(staticCacheName)
      .then( cache => {
          cache.put(request, responseCopy);
      })
    );
    return responseFromFetch;
  })

That all seems to be working well in browsers that support service workers. For legacy browsers, like Mobile Safari, there’s the much blunter caveman logic of an AppCache manifest.

Here’s the JavaScript that decides whether a browser gets the service worker or the AppCache:

if ('serviceWorker' in navigator) {
  // If service workers are supported
  navigator.serviceWorker.register('/serviceworker.js');
} else if ('applicationCache' in window) {
  // Otherwise inject an iframe to use appcache
  var iframe = document.createElement('iframe');
  iframe.setAttribute('src', '/appcache.html');
  iframe.setAttribute('style', 'width: 0; height: 0; border: 0');
  document.querySelector('footer').appendChild(iframe);
}

Either way, people are making full use of the offline nature of the book and that makes me very happy indeed.

Starting out

I had a really enjoyable time at Codebar Brighton last week, not least because Morty came along.

I particularly enjoy teaching people who have zero previous experience of making a web page. There’s something about explaining HTML and CSS from first principles that appeals to me. I especially love it when people ask lots of questions. “What does this element do?”, “Why do some elements have closing tags and others don’t?”, “Why is it textarea and not input type="textarea"?” The answer usually involves me going down a rabbit-hole of web archeology, so I’m in my happy place.

But there’s only so much time at Codebar each week, so it’s nice to be able to point people to other resources that they can peruse at their leisure. It turns out that’s it’s actually kind of tricky to find resources at that level. There are lots of great articles and tutorials out there for professional web developers—Smashing Magazine, A List Apart, CSS Tricks, etc.—but no so much for complete beginners.

Here are some of the resources I’ve found:

  • MarkSheet by Jeremy Thomas is a free HTML and CSS tutorial. It starts with an explanation of the internet, then the World Wide Web, and then web browsers, before diving into HTML syntax. Jeremy is the same guy who recently made CSS Reference.
  • Learn to Code HTML & CSS by Shay Howe is another free online book. You can buy a paper copy too. It’s filled with good, clear explanations.
  • Zero to Hero Coding by Vera Deák is an ongoing series. She’s starting out on her career as a front-end developer, so her perspective is particularly valuable.

If I find any more handy resources, I’ll link to them and tag them with “learning”.

Exploring web technologies

Last week, I had two really enjoyable experiences discussing completely opposite ends of the web technology stack.

Tuesday is Codebar day here in Brighton. Clearleft hosted it at 68 Middle Street last week. I really, really enjoy coaching at Codebar. I particularly like teaching the absolute basics of HTML and CSS. There’s something so rewarding about seeing the “a-ha!” moments when concepts click with people. I also love answering the inevitable questions that arise, like “why is it like that?”, or “how do I do this?”

Fantastic coding tonight! Great to see you all. Thanks for coming and thanks @68MiddleSt & @clearleft for having us.

Thursday was devoted to the opposite end of the spectrum. I ran a workshop at Clearleft with some developers from one of our clients. The whole day was dedicated to exploring and evaluating up-and-coming web technologies. Basically, it was a chance to geek out about all the stuff I’ve been linking to or writing about. During the workshop I ended up making a lot of use of my tagging system here on adactio.com:

Prioritising topics for discussion.

Web components and service workers ended up at the top of the list of technologies to tackle, which was fortuitous, given my recent thoughts on comparing the two:

First of all, ask the question “who benefits from this technology?” In the case of service workers, it’s the end users. They get faster websites that handle network failure better. In the case of web components, there are no direct end-user benefits. Web components exist to make developers lives easier. That’s absolutely fine, but any developer convenience gained by the use of web components can’t come at the expense of the user—that price is too high.

The next question we usually ask when we’re evaluating a technology is “how well does it work?” Personally, I think it’s just as important to ask “how well does it fail?”

Those two questions turned out to be a good framework for the whole workshop. The question of how to evaluate technologies is something I’ve been thinking about a lot lately. I’m pretty sure it will be what my next conference talk is going to be all about.

You can read more about the structure of the workshop over on the Clearleft site. I’m looking forward to running it again sometime. But I’m equally looking forward to getting back to the basics at the next Codebar.

Class teacher

ES6 introduced a whole bunch of new features to JavaScript. One of those features is the class keyword. This introduction has been accompanied by a fair amount of concern and criticism.

Here’s the issue: classes in JavaScript aren’t quite the same as classes in other programming languages. In fact, technically, JavaScript doesn’t really have classes at all. But some say that technically isn’t important. If it looks like a duck, and quacks like a duck, shouldn’t we call it a duck even if technically it’s somewhat similar—but not quite the same—species of waterfowl?

The argument for doing this is that classes are so familiar from other programming languages, that having some way of using classes in JavaScript—even if it isn’t technically the same as in other languages—brings a lot of benefit for people moving over to JavaScript from other programming languages.

But that comes with a side-effect. Anyone learning about classes in JavaScript will basically be told “here’s how classes work …but don’t look too closely.”

Now if you believe that outcomes matter more than understanding, then this is a perfectly acceptable trade-off. After all, we use computers every day without needing to understand the inner workings of every single piece of code under the hood.

It doesn’t sit well with me, though. I think that understanding how something works is important (in most cases). That’s why I favour learning underlying technologies first—HTML, CSS, JavaScript—before reaching for abstractions like frameworks and libraries. If you understand the way things work first, then your choice of framework, library, or any other abstraction is an informed choice.

The most common way that people refer to the new class syntax in JavaScript is to describe it as syntactical sugar. In other words, it doesn’t fundamentally introduce anything new under the hood, but it gives you a shorter, cleaner, nicer way of dealing with objects. It’s an abstraction. But because it’s an abstraction taken from other programming languages that work differently to JavaScript, it’s a bit of fudge. It’s a little white lie. The class keyword in JavaScript will work just fine as long as you don’t try to understand it.

My personal opinion is that this isn’t healthy.

I’ve come across two fantastic orators who cemented this view in my mind. At Render Conf in Oxford earlier this year, I had the great pleasure of hearing Ashley Williams talk about the challenges of teaching JavaScript. Skip to the 15 minute mark to hear her introduce the issues thrown up classes in JavaScript.

More recently, the mighty Kyle Simpson was on an episode of the JavaScript Jabber podcast. Skip to the 17 minute mark to hear him talk about classes in JavaScript.

(Full disclosure: Kyle also some very kind things about some of my blog posts at the end of that episode, but you can switch it off before it gets to that bit.)

Both Ashley and Kyle bring a much-needed perspective to the discussion of language design. That perspective is the perspective of a teacher.

In his essay on W3C’s design principles, Bert Bos lists learnability among the fundamental driving forces (closely tied to readability). Learnability and teachability are two sides of the same coin, and I find it valuable to examine any language decisions through that lens. With that mind, introducing a new feature into a language that comes with such low teachability value as to warrant a teacher actively telling a student not to learn how things really work …well, that just doesn’t seem right.

A little progress

I’ve got a fairly simple posting interface for my notes. A small textarea, an optional file upload, some checkboxes for syndicating to Twitter and Flickr, and a submit button.

Notes posting interface

It works fine although sometimes the experience of uploading a file isn’t great, especially if I’m on a slow connection out and about. I’ve been meaning to add some kind of Ajax-y progress type thingy for the file upload, but never quite got around to it. To be honest, I thought it would be a pain.

But then, in his excellent State Of The Gap hit parade of web technologies, Remy included a simple file upload demo. Turns out that all the goodies that have been added to XMLHttpRequest have made this kind of thing pretty easy (and I’m guessing it’ll be easier still once we have fetch).

I’ve made a little script that adds a progress bar to any forms that are POSTing data.

Feel free to use it, adapt it, and improve it. It isn’t using any ES6iness so there are some obvious candidates for improvement there.

It’s working a treat on my little posting interface. Now I can stare at a slowly-growing progress bar when I’m out and about on a slow connection.

Accessible progressive disclosure revisited

I wrote a little while back about making an accessible progressive disclosure pattern. It’s very basic—just a few ARIA properties and a bit of JavaScript sprinkled onto some basic HTML. The HTML contains a button element that toggles the aria-hidden property on a chunk of markup.

Earlier this week I had a chance to hang out with accessibility experts Derek Featherstone and Devon Persing so I took the opportunity to pepper them with questions about this pattern. My main question was “Should I automatically focus the toggled content?”

Derek’s response was very perceptive. He wanted to know why I was using a button. Good question. When you think about it, what I’m doing is pointing from one element to another. On the web, we point with links.

There are no hard’n’fast rules about this kind of thing, but as Derek put it, it helps to think about whether the action involves controlling something (use a button) or taking the user somewhere (use a link). At first glance, the progressive disclosure pattern seems to be about controlling something—toggling the appearance of another element. But if I’m questioning whether to automatically focus that element, then really I’m asking whether I want to take the user to that place in the document—in other words, linking to it.

I decided to update the markup. Here’s what I had before:

<button aria-controls="content">Reveal</button>
<div id="content"></div>

Here’s what I have now:

<a href="#content" aria-controls="content">Reveal</a>
<div id="content"></div>

The logic in the JavaScript remains exactly the same:

  1. Find any elements that have an aria-controls attribute (these were buttons, now they’re links).
  2. Grab the value of that aria-controls attribute (an ID).
  3. Hide the element with that ID by applying aria-hidden="true" and make that element focusable by adding tabindex="-1".
  4. Set aria-expanded="false" on the associated link (this attribute can be a bit confusing—it doesn’t mean that this element is not expanded; it means the element it controls is not expanded).
  5. Listen for click events on those links.
  6. Toggle the aria-hidden and aria-expanded when there’s a click event.
  7. When aria-hidden is set to false on an element (thereby revealing it), focus that element.

You can see it in action on CodePen.

See the Pen Accessible toggle (link) by Jeremy Keith (@adactio) on CodePen.

Accessible progressive disclosure

Over on The Session I have a few instances of a progressive disclosure pattern. It’s just your basic show/hide toggle: click on a button; see some more content. For example, there’s a “download” button for every tune that displays options to download the tune in different formats (ABC and midi).

To begin with, I was using the :checked pseudo-class pattern that Charlotte has documented so well. I really like that pattern. It feels nice and straightforward. But then I got some feedback from someone using the site:

the link for midi files is no longer coming up on the tune pages. I am blind so I rely on the midi’s when finding tunes for my students.

I wrote back saying the link to download midi files was revealed by the “download” option. The response:

Excellent. I have it now, I was just looking for the midi button which wasn’t there. the actual download button doesn’t read as a button under each version of the tune but now I know it’s there I know what I am doing. I am using the JAWS screen reader.

This was just one person …one person who took the time to write to me. What about other screen reader users?

I dabbled around with adding role="button" to the checkbox or the label, but that felt really icky (contradicting the inherent role of those elements) and it didn’t seem to make much difference anyway.

I decided to refactor the progressive disclosure to use JavaScript instead just CSS. I wanted to make sure that accessibility was built into the functionality, rather than just bolted on. That’s why code I’ve written doesn’t rely on the buttons having a particular class value; instead the buttons must have an aria-controls attribute that associates the button with the element it toggles (in much the same way that a for attribute associates a label with a form field).

Here’s the logic:

  1. Find any elements that have an aria-controls attribute (these should be buttons).
  2. Grab the value of that aria-controls attribute (an ID).
  3. Hide the element with that ID by applying aria-hidden="true" and make that element focusable by adding tabindex="-1".
  4. Set aria-expanded="false" on the associated button (this attribute can be a bit confusing—it doesn’t mean that this element is not expanded; it means the element it controls is not expanded).
  5. Listen for click events on those buttons.
  6. Toggle the aria-hidden and aria-expanded when there’s a click event.
  7. When aria-hidden is set to false on an element (thereby revealing it), focus that element.

You can see it action on CodePen.

I’m still playing around with this. I think the :focus styles are probably far too subtle right now—see this excellent presentation from Laura Palmaro for more on that. I’m also not sure if the revealed content should automatically take focus. I’ll see if I can get some feedback from people on The Session using screen readers—there’s quite a few of them.

Feel free to use my code but you might want to check out Jason’s code to do the same thing—his is bound to be nicer to work with.

Update: In response to this discussion, I’ve decided not to automatically focus the expanded content.