Tag Archives: CSS preprocessors

Making Bootstrap work with the WordPress Block Editor

tl;dr: You need to load Bootstrap’s CSS in the 'wp_enqueue_scripts' hook with a priority lower than 10.

Where do I begin with this one? First, some foundational details: I’m old school. I’ve been a professional web developer/designer since 1996. I’ve embraced new technologies as they come along, but I tend to bristle at things that are either a) not an open standard or b) need to be compiled.

I refused to use Flash. In the end I was proved right, as open web technologies supplanted it. Flash is dead, and the open web is not. I still refuse to use CSS preprocessors for a similar reason. They’re a non-standard workaround to limitations in the current standard. They fragment the landscape instead of pushing the standard forward. And as CSS variables have gained wide browser support, preprocessors are beginning to look as pointless as Flash.

Now the thing I hate is npm — or any similar tech that requires me to run shell scripts and compile anything. I’ve long since embraced server-side scripting, using open source libraries like jQuery, and even using a pre-built CMS (or CMS-ish system) like WordPress. (Yes, for many years I rolled my own CMSes.) The bottom line for me is, if it’s code I can download simply and treat as a “black box,” fine. But if it’s something I need to get my hands dirty in, I shouldn’t need anything to work with it but a text editor.

All of that to say, I am having a bit of a time with where things are going these days with Gutenberg, a.k.a. the WordPress Block Editor. And I haven’t exactly been quiet about it here.

This week I needed to extend the Block Editor by creating a carousel/slideshow block. Yep, I’ve rolled my own with these for many years as well, but this time around I decided I wanted to work with something pre-built, so I settled on the one in Bootstrap. I don’t really need all of Bootstrap (although I suspect over time I will need more of it), but customizing it requires using npm, so I decided to go ahead and include the entire pre-compiled package in my theme.

That’s when the problems began.

Oh, the carousel works great! But I spent a bunch of time yesterday trying to figure out why the custom background color and fonts defined in my theme.json file were being ignored… especially since they’re right there in the inline CSS inside the <head> of every page.

Don’t even get me started on inline CSS, or the way so many people in the industry seem to worship PageSpeed Insights. Once again we’re skating to where the puck is, instead of where it’s going, and to stretch the analogy to the limit, we’re melting all of the ice in front of it too. This is not the way to move web development forward intelligently.

Ah-hem.

Eventually I worked out what’s happening. WordPress, historically, was designed to allow you to define dependencies, so you could load CSS and JavaScript in a logical manner. Gutenberg/Block Editor throws all of this out the window with this inline CSS. Certain “critical” inline CSS for the Block Editor gets loaded immediately regardless of the dependencies you put into wp_enqueue_style(). The result being, styles defined (indirectly, in a way more convoluted way than vanilla CSS) in my theme.json file were appearing before the Bootstrap CSS file was loaded. And since I’m using the compiled Bootstrap instead of a custom npm build, there’s a bunch of “general” CSS it’s throwing in, including color and font definitions on the <body> tag that override Gutenberg’s earlier inline CSS.

Fortunately, someone else had the same problem and figured out a solution. But since, in 2022, spammers overrun any forum thread that’s left open too long, the thread was already locked and I couldn’t express my appreciation to the poster who shared it. So I’m writing this blog post instead.

The trick is to load any third-party CSS that you might need to override using a separate function called on the 'wp_enqueue_scripts' hook, with a low priority number (less than 10, since that’s the magic default).

Here’s a generalized version of the code I’m using:

function my_enqueue_scripts_early() {

    $ver = '1.0.0'; // Your theme version; could also be a class property, constant, global variable, etc.

    wp_enqueue_style('bootstrap-style', get_theme_file_uri('vendors/bootstrap/bootstrap.min.css'), array(), $ver);
    wp_enqueue_script('bootstrap', get_theme_file_uri('vendors/bootstrap/bootstrap.bundle.min.js'), array('jquery'), $ver);

}
add_action('wp_enqueue_scripts', 'my_enqueue_scripts_early', 8);

The (highly biased) case against CSS preprocessors

Everybody who’s anybody is using CSS preprocessors!

Or so it feels. I’m an old-school vanilla CSS curmudgeon, and the more I’ve dipped my toes into working with CSS preprocessors (specifically, SCSS with Compass), the less I like them.

As I see it, there are three main problems with vanilla CSS:

No variables. Honestly this is probably the only problem I really have with CSS. I’d like to be able to set variables for things like colors that I use throughout a site. To a lesser extent, I see the benefit of “mixins” — reusable chunks of CSS.

Redundant code. It really depends on how you conceptualize your CSS structures, but it is very easy to fall into a habit of writing the same CSS code over and over again, resulting in bloated, hard to maintain files. While I am guilty of this just like anyone else, I find that if you format your CSS code properly you can combine properties efficiently to avoid redundancy without needing any external solutions.

Lack of programmatic logic. Here I’m thinking about things like conditional statements, and also math operations. This is probably as much of a strength as a weakness. CSS is a stylesheet, not a program. It’s a set of rules to be applied to formatting a document. There’s nothing programmatic about it. But still, as CSS selectors become more complicated and convoluted, it is clear that in some cases light programming logic would be helpful.

The real question is, do CSS preprocessors actually solve these problems? Or, more specifically, do they solve them without introducing new problems that are at least as bad as the ones they’re trying to fix?

For me the answer has been, and continues to be, no, they don’t. But I’m trying to get a more tangible explanation for why that is, rather than the simple gut feeling that’s been driving me away from using them up to this point.

What are other people saying?

My first stop in trying to answer this question of why I dislike CSS preprocessors was Google. I wanted to see what other people were saying, pro and con. Here are some interesting blog posts I found, going back a few years to the early (or at least earlier) days of CSS preprocessors:

The problem with CSS pre-processors
This article by Miller Medeiros was the first one I came across a few months ago when I initially pondered this question, and at the time it was all I needed to satisfy myself that I was not crazy for wanting to avoid CSS preprocessors.

So, assuming preprocessors do solve the problems with vanilla CSS, what are the problems they introduce? And how bad are they, really?

I need to get specific to my own situation for a minute here. I have a former coworker who is a firm believer in SCSS, and now that he’s gone, I’m left to maintain and extend the code he was writing. This experience casts my aversion to CSS preprocessors into stark relief.

Maintenance can be a challenge

The most obvious issue with using a preprocessor is that the output CSS is not exactly easy to hand edit, and worse, you shouldn’t hand edit it, because your changes don’t end up back in the original SCSS (or whatever format you’re using) files. If someone else goes back in later and edits the original SCSS and generates new CSS, your changes will get lost.

But let’s set that matter aside for a minute. In a broader sense, one of the key challenges for any web developer is to build code that is easy to maintain. Not just for you to maintain, but for whoever comes after you to maintain. Face it, you’re not going to be working on this project forever. At some point, someone else is either going to need to take it over, or throw away what you did and start fresh.

If you’ve ever jumped into an existing project midstream, or been handed the task of maintaining something someone else built — especially if it’s something built by someone who is no longer around to answer your questions — you know that it’s rarely an ideal situation. Even if the previous developer left copious documentation, it can take hours of picking apart their code to really get a firm understanding of how it all works. This is true with plain CSS too, but at least with plain CSS it’s a lot less work to track down a particular piece of troublesome code.

It’s non-standard

What happens when certain features of your favorite preprocessor get rolled into a future version of vanilla CSS? What happens if similar (but incompatible) features of a different preprocessor become the standard? In short, what if everything you’re doing right now becomes obsolete? How long are you going to hang on to doing things your old way with your no-longer-relevant preprocessor, before you have to scrap it and start over, or at least rewrite big chunks of your code to fit the new way everyone is doing things?

Call me a curmudgeon, but having been a professional web developer for over 18 years I’ve seen a lot of technologies and design trends come and go. I’ve always been skeptical of anything non-standard. I never used VBScript or ActiveX, I never embraced Flash, and in general I’ve done everything I could to both champion and adhere to open standards as much as possible throughout my career.

Suffice to say, resisting CSS preprocessors is just in my blood. They just don’t feel right to me. I’d rather do without features I want, if they’re not part of the standard, than resort to a non-standard workaround to make them happen… especially if it looks like there’s a reasonable chance they’ll be added to the standard at some point in the not-too-distant future.