Tags: class

9

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Problem space

Adam Wathan wrote an article recently called CSS Utility Classes and “Separation of Concerns”. In it, he documents his journey through different ways of thinking about CSS. A lot of it is really familiar.

Phase 1: “Semantic” CSS

Ah, yes! If you’ve been in the game for a while then this will be familiar to you. The days when we used to strive to keep our class names to a minimum and use names that described the content. But, as Adam points out:

My markup wasn’t concerned with styling decisions, but my CSS was very concerned with my markup structure.

Phase 2: Decoupling styles from structure

This is the work pioneered by Nicole with OOCSS, and followed later by methodologies like BEM and SMACSS.

This felt like a huge improvement to me. My markup was still “semantic” and didn’t contain any styling decisions, and now my CSS felt decoupled from my markup structure, with the added bonus of avoiding unnecessary selector specificity.

Amen!

But then Adam talks about the issues when you have two visually similar components that are semantically very different. He shows a few possible solutions and asks this excellent question:

For the project you’re working on, what would be more valuable: restyleable HTML, or reusable CSS?

For many projects reusable CSS is the goal. But not all projects. On the Code For America project, the HTML needed to be as clean as possible, even if that meant more brittle CSS.

Phase 3: Content-agnostic CSS components

Naming things is hard:

The more a component does, or the more specific a component is, the harder it is to reuse.

Adam offers some good advice on naming things for maximum reusability. It’s all good stuff, and this would be the point at which I would stop. At this point there’s a nice balance between reusability, readability, and semantic meaning.

But Adam goes further…

Phase 4: Content-agnostic components + utility classes

Okay. The occasional utility class (for alignment and clearing) can be very handy. This is definitely the point to stop though, right?

Phase 5: Utility-first CSS

Oh God, no!

Once this clicked for me, it wasn’t long before I had built out a whole suite of utility classes for common visual tweaks I needed, things like:

  • Text sizes, colors, and weights
  • Border colors, widths, and positions
  • Background colors
  • Flexbox utilities
  • Padding and margin helpers

If one drink feels good, then ten drinks must be better, right?

At this point there is no benefit to even having an external stylesheet. You may as well use inline styles. Ah, but Adam has anticipated this and counters with this difference between inline styles and having utility classes for everything:

You can’t just pick any value want; you have to choose from a curated list.

Right. But that isn’t a technical solution, it’s a cultural one. You could just as easily have a curated list of allowed inline style properties and values. If you are in an environment where people won’t simply create a new utility class every time they want to style something, then you are also in an environment where people won’t create new inline style combinations every time they want to style something.

I think Adam has hit on something important here, but it’s not about utility classes. His suggestion of “utility-first CSS” will only work if the vocabulary is strictly adhered to. For that to work, everyone touching the code needs to understand the system and respect the boundaries of it. That understanding and respect is far, far more important than any particular way of structuring HTML and CSS. No technical solution can replace that sort of agreement …not even slapping !important on every declaration to make them immutable.

I very much appreciate the efforts that people have put into coming up with great naming systems and methodologies, even the ones I don’t necessarily agree with. They’re all aiming to make that overlap of HTML and CSS less painful. But the really hard problem is where people overlap.

Teaching in Porto, day five

For the final day of the week-long masterclass, I had no agenda. This was a time for the students to work on their own projects, but I was there to answer any remaining questions they might have.

As I suspected, the people with the most interest and experience in development were the ones with plenty of questions. I was more than happy to answer them. With no specific schedule for the day, we were free to merrily go chasing down rabbit holes.

SVG? Sure, I’d be happy to talk about that. More JavaScript? My pleasure! Databases? Not really my area of expertise, but I’m more than willing to share what I know.

It was a fun day. The centrepiece was a most excellent lunch across the river at a really traditional seafood place.

At the very end of the day, after everyone else had gone, I sat down with Tiago to discuss how the week went. Overall, I was happy. I was nervous going into this masterclass—I had never done a whole week of teaching—but based on the feedback I got, I think I did okay. There were times when I got impatient, and I wish I could turn back the clock and erase those moments. I noticed that those moments tended to occur when it was time for hands-on-keyboards coding: “no, not like that—like this!” I need to get better at handling those situations. But when we working on paper, or having stand-up discussions, or when I was just geeking out on a particular topic, everything felt quite positive.

All in all, this week has been a great experience. I know it sounds like a cliché, but I felt it was a real honour and a privilege to be involved with the New Digital School. I’ve enjoyed doing hands-on teaching, and I’d like to do more of it.

Teaching in Porto, day four

Day one covered HTML (amongst other things), day two covered CSS, and day three covered JavaScript. Each one of those days involved a certain amount of hands-on coding, with the students getting their hands dirty with angle brackets, curly braces, and semi-colons.

Day four was a deliberate step away from all that. No more laptops, just paper. Whereas the previous days had focused on collaboratively working on a single document, today I wanted everyone to work on a separate site.

The sites were generated randomly. I made five cards with types of sites on them: news, social network, shopping, travel, and learning. Another five cards had subjects: books, music, food, pets, and cars. And another five cards had audiences: students, parents, the elderly, commuters, and teachers. Everyone was dealt a random card from each deck, resulting in briefs like “a travel site about food for the elderly” or “a social network about music for commuters.”

For a bit of fun, the first brainstorming exercise (run as a 6-up) was to come with potential names for this service—4 minutes for 6 ideas. Then we went around the table, shared the ideas, got feedback, and settled on the names.

Now I asked everyone to come up with a one-sentence mission statement for their newly-named service. This was a good way of teasing out the most important verbs and nouns, which led nicely into the next task: answering the question “what is the core functionality?”

If that sounds familiar, it’s because it’s the first part of the three-step process I outlined in Resilient Web Design:

  1. Identify core functionality.
  2. Make that functionality available using the simplest possible technology.
  3. Enhance!

We did some URL design, figuring out what structures would make sense for straightforward GET requests, like:

  • /things
  • /things/ID

Then, once it was clear what the primary “thing” was (a car, a book, etc.), I asked them to write down all the pieces that might appear on such a page; one post-it note per item e.g. “title”, “description”, “img”, “rating”, etc.

The next step involved prioritisation. They took those post-it notes and put them on the wall, but they had to put them in a vertical line from top to bottom in decreasing order of importance. This can be a challenge, but it’s better to solve these problems now rather than later.

Okay. I know asked them to “mark up” those vertical lists of post-it notes: writing HTML tag names by each one. By doing this before doing any visual design, it meant they were thinking about the meaning of the content first.

After that, we did a good ol’ fashioned classic 6-up sketching exercise, followed by critique (including a “designated dissenter” for each round). At this point, I was encouraging them to go crazy with ideas—they already had the core functionality figured out (with plain ol’ client/server requests and responses) so they could all the bells and whistles they wanted on top of that.

We finished up with a discussion of some of those bells and whistles, and how they could be used to improve the user experience: Ajax, geolocation, service workers, notifications, background sync …the sky’s the limit.

It was a whirlwind tour for just one day but I think it helped emphasise the importance of thinking about the fundamentals before adding enhancements.

This marked the end of the structured masterclass lessons. Tomorrow I’m around to answer any miscellaneous questions (if I can) and chat to the students individually while they work on their term projects.

Teaching in Porto, day three

Day two ended with a bit of a cliffhanger as I had the students mark up a document, but not yet style it. In the morning of day three, the styling began.

Rather than just treat “styling” as one big monolithic task, I broke it down into typography, colour, negative space, and so on. We time-boxed each one of those parts of the visual design. So everyone got, say, fifteen minutes to write styles relating to font families and sizes, then another fifteen minutes to write styles for colours and background colours. Bit by bit, the styles were layered on.

When it came to layout, we closed the laptops and returned to paper. Everyone did a quick round of 6-up sketching so that there was plenty of fast iteration on layout ideas. That was followed by some critique and dot-voting of the sketches.

Rather than diving into the CSS for layout—which can get quite complex—I instead walked through the approach for layout; namely putting all your layout styles inside media queries. To explain media queries, I first explained media types and then introduced the query part.

I felt pretty confident that I could skip over the nitty-gritty of media queries and cross-device layout because the next masterclass that will be taught at the New Digital School will be a week of responsive design, taught by Vitaly. I just gave them a taster—Vitaly can dive deeper.

By lunch time, I felt that we had covered CSS pretty well. After lunch it was time for the really challenging part: JavaScript.

The reason why I think JavaScript is challenging is that it’s inherently more complex than HTML or CSS. Those are declarative languages with fairly basic concepts at heart (elements, attributes, selectors, etc.), whereas an imperative language like JavaScript means entering the territory of logic, loops, variables, arrays, objects, and so on. I really didn’t want to get stuck in the weeds with that stuff.

I focused on the combination of JavaScript and the Document Object Model as a way of manipulating the HTML and CSS that’s already inside a browser. A lot of that boils down to this pattern:

When (some event happens), then (take this action).

We brainstormed some examples of this e.g. “When the user submits a form, then show a modal dialogue with an acknowledgement.” I then encouraged them to write a script …but I don’t mean a script in the JavaScript sense; I mean a script in the screenwriting or theatre sense. Line by line, write out each step that you want to accomplish. Once you’ve done that, translate each line of your English (or Portuguese) script into JavaScript.

I did quick demo as a proof of concept (which, much to my surprise, actually worked first time), but I was at pains to point out that they didn’t need to remember the syntax or vocabulary of the script; it was much more important to have a clear understanding of the thinking behind it.

With the remaining time left in the day, we ran through the many browser APIs available to JavaScript, from the relatively simple—like querySelector and Ajax—right up to the latest device APIs. I think I got the message across that, using JavaScript, there’s practically no limit to what you can do on the web these days …but the trick is to use that power responsibly.

At this point, we’ve had three days and we’ve covered three layers of web technologies: HTML, CSS, and JavaScript. Tomorrow we’ll take a step back from the nitty-gritty of the code. It’s going to be all about how to plan and think about building for the web before a single line of code gets written.

Teaching in Porto, day two

The second day in this week-long masterclass was focused on CSS. But before we could get stuck into that, there were some diversions and tangents brought on by left-over questions from day one.

This was not a problem. Far from it! The questions were really good. Like, how does a web server know that someone has permission to carry out actions via a POST request? What a perfect opportunity to talk about state! Cue a little history lesson on the web’s beginning as a deliberately stateless medium, followed by the introduction of cookies …for good and ill.

We also had a digression about performance, file sizes, and loading times—something I’m always more than happy to discuss. But by mid-morning, we were back on track and ready to tackle CSS.

As with the first day, I wanted to take a “long zoom” look at design and the web. So instead of diving straight into stylesheets, we first looked at the history of visual design: cave paintings, hieroglyphs, illuminated manuscripts, the printing press, the Swiss school …all of them examples of media where the designer knows where the “edges” of the canvas lie. Not so with the web.

So to tackle visual design on the web, I suggested separating layout from all the other aspects of visual design: colour, typography, contrast, negative space, and so on.

At this point we were ready to start thinking in CSS. I started by pointing out that all CSS boils down to one pattern:

selector {
  property: value;
}

The trick, then, is to convert what you want into that pattern. So “I want the body of the page to be off-white with dark grey text” in English is translated into the CSS:

body {
  background-color: rgb(225,225,255);
  color: rgb(51,51,51);
}

…and so one for type, contrast, hierarchy, and more.

We started applying styles to the content we had collectively marked up with post-it notes on day one. Then the students split into groups of two to create an HTML document each. Tomorrow they’ll be styling that document.

There were two important links that come up over the course of day two:

  1. A Dao Of Web Design by John Allsopp, and
  2. The CSS Zen Garden.

If all goes according to plan, we’ll be tackling the third layer of the web technology stack tomorrow: JavaScript.

Teaching in Porto, day one

Today was the first day of the week long “masterclass” I’m leading here at The New Digital School in Porto.

When I was putting together my stab-in-the-dark attempt to provide an outline for the week, I labelled day one as “How the web works” and gave this synopsis:

The internet and the web; how browsers work; a history of visual design on the web; the evolution of HTML and CSS.

There ended up being less about the history of visual design and CSS (we’ll cover that tomorrow) and more about the infrastructure that the web sits upon. Before diving into the way the web works, I thought it would be good to talk about how the internet works, which led me back to the history of communication networks in general. So the day started from cave drawings and smoke signals, leading to trade networks, then the postal system, before getting to the telegraph, and then telephone networks, the ARPANET, and eventually the internet. By lunch time we had just arrived at the birth of the World Wide Web at CERN.

It wasn’t all talk though. To demonstrate a hub-and-spoke network architecture I had everyone write down someone else’s name on a post-it note, then stand in a circle around me, and pass me (the hub) those messages to relay to their intended receiver. Later we repeated this exercise but with a packet-switching model: everyone could pass a note to their left or to their right. The hub-and-spoke system took almost a minute to relay all six messages; the packet-switching version took less than 10 seconds.

Over the course of the day, three different laws came up that were relevant to the history of the internet and the web:

Metcalfe’s Law
The value of a network is proportional to the square of the number of users.
Postel’s Law
Be conservative in what you send, be liberal in what you accept.
Sturgeon’s Law
Ninety percent of everything is crap.

There were also references to the giants of hypertext: Ted Nelson, Vannevar Bush, and Douglas Engelbart—for a while, I had the mother of all demos playing silently in the background.

After a most-excellent lunch in a nearby local restaurant (where I can highly recommend the tripe), we started on the building blocks of the web: HTTP, URLs, and HTML. I pulled up the first ever web page so that we could examine its markup and dive into the wonder of the A element. That led us to the first version of HTML which gave us enough vocabulary to start marking up documents: p, h1-h6, ol, ul, li, and a few others. We went around the room looking at posters and other documents pinned to the wall, and starting marking them up by slapping on post-it notes with opening and closing tags on them.

At this point we had covered the anatomy of an HTML element (opening tags, closing tags, attribute names and attribute values) as well as some of the history of HTML’s expanding vocabulary, including elements added in HTML5 like section, article, and nav. But so far everything was to do with marking up static content in a document. Stepping back a bit, we returned to HTTP, and talked about difference between GET and POST requests. That led in to ways of sending data to a server, which led to form fields and the many types of inputs at our disposal: text, password, radio, checkbox, email, url, tel, datetime, color, range, and more.

With that, the day drew to a close. I feel pretty good about what we covered. There was a lot of groundwork, and plenty of history, but also plenty of practical information about how browsers interpret HTML.

With the structural building blocks of the web in place, tomorrow is going to focus more on the design side of things.

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.

Pseudo and pseudon’t

I like CSS pseudo-classes. They come in handy for adding little enhancements to interfaces based on interaction.

Take the form-related pseudo-classes, for example: :valid, :invalid, :required, :in-range, and many more.

Let’s say I want to adjust the appearance of an element based on whether it has been filled in correctly. I might have an input element like this:

<input type="email" required>

Then I can write some CSS to put green border on it once it meets the minimum requirements for validity:

input:valid {
  border: 1px solid green;
}

That works, but somewhat annoyingly, the appearance will change while the user is still typing in the field (as soon as the user types an @ symbol, the border goes green). That can be distracting, or downright annoying.

I only want to display the green border when the input is valid and the field is not focused. Luckily for me, those last two words (“not focused”) map nicely to some more pseudo-classes: not and focus:

input:not(:focus):valid {
  border: 1px solid green;
}

If I want to get really fancy, I could display an icon next to form fields that have been filled in. But to do that, I’d need more than a pseudo-class; I’d need a pseudo-element, like :after

input:not(:focus):valid::after {
  content: '✓';
}

…except that won’t work. It turns out that you can’t add generated content to replaced elements like form fields. I’d have to add a regular element into my markup, like this:

<input type="email" required>
<span></span>

So I could style it with:

input:not(:focus):valid + span::after {
  content: '✓';
}

But that feels icky.

Update: See this clever flexbox technique by Hugo Giraudel for a potential solution.

Classy values

Two articles were published today that take diametrically opposed viewpoints on how developers should be using CSS:

I don’t want to attempt to summarise either article as they both give fairly lengthy in-depth explanations of their positions, although I find that they’re both a bit extreme. They’re both ostensibly about CSS, though in reality they’re more about the class values we add to our HTML (and remember, as Ben points out, class is an HTML attribute; there’s no such thing as CSS classes).

Thierry advocates entirely presentational values, like this:

    <div class="Bfc M-10">

Meanwhile Ben argues that this makes the markup less readable and maintainable, and that we should strive to have human-readable markup, more like the example that Thierry dismisses as inefficient:

    <div class="media">

Here’s my take on it: this isn’t an either/or situation. I think that both extremes are problematic. If you make your class values entirely presentational in order to make your CSS more modular, you’re offloading a maintainability expense onto your markup. But if you stick to strictly semantically-meaningful class values, your CSS is probably going to be a lot harder to write in a modular, maintainable way.

Fortunately, the class attribute takes a space-separated list of values. That means you can have your OOCSS/SMACSS/BEM cake and semantically eat it too:

<div class="media Bfc M-10">

The “media” value describes the content, which is traditionally what a semantically-meaningful class name is supposed to do. Meanwhile, the “Bfc” and “M-10” values say nothing about the nature of the content, but everything about how it should be displayed.

Is it wasteful to use a class value that is never used by the CSS? Possibly. But I think it serves a useful purpose for any humans (developer or end user) reading the markup, or potentially machines parsing/scraping the markup.

I’ve used class values that never get touched by CSS. Here on adactio.com, if I want to mark up something as being a scare quote, I’ll write:

<q class="scare">scare quote</q>

But nowhere in my CSS do I use a selector like this:

q.scare { }

Speaking of scare quotes….

Both of the aforementioned articles begin by establishing that their approach is the minority viewpoint and that web developers everywhere are being encouraged to adapt the other way of working.

Ben writes:

Most disconcertingly, these methodologies have seen widespread adoption thanks to prominent bloggers evangelising their usage as ‘best practice’.

Meanwhile Thierry writes:

But when it comes to the presentational layer, “best practice” goes way beyond the separation of resources.

Perhaps both authors have more in common than they realise: they certainly seem to agree that any methodology you don’t agree with should be labelled as a best practice and wrapped in scare quotes.

Frankly, I think this attitude does more harm than good. A robust argument should stand on its own strengths—it shouldn’t rely on knocking down straw men that supposedly represent the opposing viewpoint.

Some of the trigger words that grind my gears are: dogma, zealot, purist, sacred, and pedant. I’ve mentioned this before:

Whenever someone labels those they disagree with as “dogmatic” or “purist”, it’s a lazy meaningless barb (like calling someone a hipster). “I’m passionate; you’re dogmatic. I sweat the details; you’re a purist.” Even when I agree completely with the argument being made—as was the case withAndy’s superb talk at South by Southwest this year—I cringe to hear the “dogma” attack employed: especially when the argument is strong enough to stand up on its own without resorting to Croftian epithets.

That’s what I was getting at when I tried to crack this joke on Twitter:

…but all I ended up doing was making a cheap shot about designers (and developers for that matter), which wasn’t my intention. The point I was intending to make was that we all throw a lot of stones from our glasses houses.

So if you’re going to write an article about the right way to do something, don’t start by labelling dissenting schools of thought as dogmatic or purist.

Physician, heal thyself.