Tags: languages

12

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Wednesday, January 16th, 2019

Use the :lang pseudo-class over the lang attribute selector for language-specific styles

This is a great explanation of the difference between the [lang] and :lang CSS selectors. I wouldn’t even have thought’ve the differences so this is really valuable to me.

Saturday, December 29th, 2018

The 100 Year Web (In Praise of XML)

I don’t agree with Steven Pemberton on a lot of things—I’m not a fan of many of the Semantic Web technologies he likes, and I think that the Robustness Principle is well-suited to the web—but I always pay attention to what he has to say. I certainly share his concern that migrating everything to JavaScript is not good for interoperability:

This is why there are so few new elements in HTML5: they haven’t done any design, and instead said “if you need anything, you can always do it in Javascript”.

And they all have.

And they are all different.

Read this talk transcript, and even if you don’t agree with everything in it today, you may end up coming back to it in the future. He’s playing the long game:

The web is the way now that we distribute information. We will need the web pages we create now to be readable in 100 years time, just as we can still read 100-year-old books.

Requiring a webpage to depend on a particular 100-year-old implementation of Javascript is not exactly evidence of future-thinking.

Tuesday, December 18th, 2018

Stop Learning Frameworks – Lifehacks for Developers by Eduards Sizovs

It’s a terribly clickbaity (and negatively phrased) title, but if you turn it around, there’s some good advcie in here for deciding where to focus when it comes to dev technology:

  • Programming languages are different, but design smells are alike.
  • Frameworks are different, but the same design patterns shine through.
  • Developers are different, but rules of dealing with people are uniform.

Thursday, December 6th, 2018

Big ol’ Ball o’ JavaScript | Brad Frost

Backend logic? JavaScript. Styles? We do that in JavaScript now. Markup? JavaScript. Anything else? JavaScript.

Historically, different languages suggested different roles. “This language does style.” “This language does structure.” But now it’s “This JavaScript does style.” “This JavaScript does structure.” “This JavaScript does database queries.”

Monday, December 3rd, 2018

Programming CSS

There’s a worrying tendency for “real” programmers look down their noses at CSS. It’s just a declarative language, they point out, not a fully-featured programming language. Heck, it isn’t even a scripting language.

That may be true, but that doesn’t mean that CSS isn’t powerful. It’s just powerful in different ways to traditional languages.

Take CSS selectors, for example. At the most basic level, they work like conditional statments. Here’s a standard if statement:

if (condition) {
// code here
}

The condition needs to evaluate to true in order for the code in the curly braces to be executed. Sound familiar?

condition {
// styles here
}

That’s a very simple mapping, but what if the conditional statement is more complicated?

if (condition1 && condition2) {
// code here
}

Well, that’s what the decendant selector does:

condition1 condition2 {
// styles here
}

In fact, we can get even more specific than that by using the child combinator, the sibling combinator, and the adjacent sibling combinator:

  • condition1 > condition2
  • condition1 ~ condition2
  • condition2 + condition2

AND is just one part of Boolean logic. There’s also OR:

if (condition1 || condition2) {
// code here
}

In CSS, we use commas:

condition1, condition2 {
// styles here
}

We’ve even got the :not() pseudo-class to complete the set of Boolean possibilities. Once you add quantity queries into the mix, made possible by :nth-child and its ilk, CSS starts to look Turing complete. I’ve seen people build state machines using the adjacent sibling combinator and the :checked pseudo-class.

Anyway, my point here is that CSS selectors are really powerful. And yet, quite often we deliberately choose not to use that power. The entire raison d’être for OOCSS, BEM, and Smacss is to deliberately limit the power of selectors, restricting them to class selectors only.

On the face of it, this might seem like an odd choice. After all, we wouldn’t deliberately limit ourselves to a subset of a programming language, would we?

We would and we do. That’s what templating languages are for. Whether it’s PHP’s Smarty or Twig, or JavaScript’s Mustache, Nunjucks, or Handlebars, they all work by providing a deliberately small subset of features. Some pride themselves on being logic-less. If you find yourself trying to do something that the templating language doesn’t provide, that’s a good sign that you shouldn’t be trying to do it in the template at all; it should be in the controller.

So templating languages exist to enforce simplicity and ensure that the complexity happens somewhere else. It’s a similar story with BEM et al. If you find you can’t select something in the CSS, that’s a sign that you probably need to add another class name to the HTML. The complexity is confined to the markup in order to keep the CSS more straightforward, modular, and maintainable.

But let’s not forget that that’s a choice. It’s not that CSS in inherently incapable of executing complex conditions. Quite the opposite. It’s precisely because CSS selectors (and the cascade) are so powerful that we choose to put guard rails in place.

Thursday, October 4th, 2018

Declaration

I like the robustness that comes with declarative languages. I also like the power that comes with imperative languages. Best of all, I like having the choice.

Take the video and audio elements, for example. If you want, you can embed a video or audio file into a web page using a straightforward declaration in HTML.

<audio src="..." controls><!-- fallback goes here --></audio>

Straightaway, that covers 80%-90% of use cases. But if you need to do more—like, provide your own custom controls—there’s a corresponding API that’s exposed in JavaScript. Using that API, you can do everything that you can do with the HTML element, and a whole lot more besides.

It’s a similar story with animation. CSS provides plenty of animation power, but it’s limited in the events that can trigger the animations. That’s okay. There’s a corresponding JavaScript API that gives you more power. Again, the CSS declarations cover 80%-90% of use cases, but for anyone in that 10%-20%, the web animation API is there to help.

Client-side form validation is another good example. For most us, the HTML attributes—required, type, etc.—are probably enough most of the time.

<input type="email" required />

When we need more fine-grained control, there’s a validation API available in JavaScript (yes, yes, I know that the API itself is problematic, but you get the point).

I really like this design pattern. Cover 80% of the use cases with a declarative solution in HTML, but also provide an imperative alternative in JavaScript that gives more power. HTML5 has plenty of examples of this pattern. But I feel like the history of web standards has a few missed opportunities too.

Geolocation is a good example of an unbalanced feature. If you want to use it, you must use JavaScript. There is no declarative alternative. This doesn’t exist:

<input type="geolocation" />

That’s a shame. Anyone writing a form that asks for the user’s location—in order to submit that information to a server for processing—must write some JavaScript. That’s okay, I guess, but it’s always going to be that bit more fragile and error-prone compared to markup.

(And just in case you’re thinking of the fallback—which would be for the input element to be rendered as though its type value were text—and you think it’s ludicrous to expect users with non-supporting browsers to enter latitude and longitude coordinates by hand, I direct your attention to input type="color": in non-supporting browsers, it’s rendered as input type="text" and users are expected to enter colour values by hand.)

Geolocation is an interesting use case because it only works on HTTPS. There are quite a few JavaScript APIs that quite rightly require a secure context—like service workers—but I can’t think of a single HTML element or attribute that requires HTTPS (although that will soon change if we don’t act to stop plans to create a two-tier web). But that can’t have been the thinking behind geolocation being JavaScript only; when geolocation first shipped, it was available over HTTP connections too.

Anyway, that’s just one example. Like I said, it’s not that I’m in favour of declarative solutions instead of imperative ones; I strongly favour the choice offered by providing declarative solutions as well as imperative ones.

In recent years there’s been a push to expose low-level browser features to developers. They’re inevitably exposed as JavaScript APIs. In most cases, that makes total sense. I can’t really imagine a declarative way of accessing the fetch or cache APIs, for example. But I think we should be careful that it doesn’t become the only way of exposing new browser features. I think that, wherever possible, the design pattern of exposing new features declaratively and imperatively offers the best of the both worlds—ease of use for the simple use cases, and power for the more complex use cases.

Previously, it was up to browser makers to think about these things. But now, with the advent of web components, we developers are gaining that same level of power and responsibility. So if you’re making a web component that you’re hoping other people will also use, maybe it’s worth keeping this design pattern in mind: allow authors to configure the functionality of the component using HTML attributes and JavaScript methods.

Tuesday, June 12th, 2018

Resilient, Declarative, Contextual

This is really good breakdown of what’s different about CSS (compared to other languages).

These differences may feel foreign, but it’s these differences that make CSS so powerful. And it’s my suspicion that developers who embrace these things, and have fully internalized them, tend to be far more proficient in CSS.

Thursday, September 21st, 2017

Web truths: CSS is not real programming | Christian Heilmann

A lot of “CSS is not real programming” arguments are a basic misunderstanding what CSS is there to achieve. If you want full control over and interface and strive for pixel perfection – don’t use it. If you want to build an interface for an inclusive and diverse web, CSS is a great tool.

Christian does a good job of describing the much-misunderstood declarative nature of CSS.

Also:

In any case, belittling people who write CSS and considering them not real developers is arrogant nonsense.

Thursday, April 20th, 2017

There are maps for these territories | Clearleft

A great piece from Danielle on the different mental models needed for different languages. When someone describes a language—like CSS—as “broken”, it may well be that there’s a mismatch in mental models.

CSS isn’t a programming language. It’s a stylesheet language. We shouldn’t expect it to behave like a programming language. It has its own unique landscape and structures, ones that people with programming language mental maps might not expect.

I believe that this mismatch of expectation is what has led to the current explosion of CSS-in-JS solutions. Confronted with a language that seems arbitrary and illogical, and having spent little or no time exposed to the landscape, developers dismiss CSS as ‘broken’ and use systems that either sweep it under the rug, or attempt to force it into alignment with the landscape of a programming language — often sacrificing some of the most powerful features of CSS.

Thursday, March 23rd, 2017

Flags are not languages – A blog about designing global user experiences: beyond language, location & culture.

It’s a bit finger-pointy but this blog should be useful for anyone working on internationalisation.

This blog has two general aims: to show the fundamental flaws in using flags to represent languages and how to create good experiences when dealing with multilingual and multi-regional content.

Wednesday, December 28th, 2016

Google Noto Fonts

Google’s Noto (short for no-tofu; tofu being the rectangle of unicode sadness) is certainly ambitious. It has glyphs from pretty much every known alphabet …including Ogham and Linear B!

Tuesday, June 28th, 2016

The Languages Which Almost Were CSS - Eager Blog

A wonderful deep dive into the history of styling languages before CSS. I love spelunking down these internet history potholes—fascinating stuff!