Using BEM Syntax with Sass 3.3

As you might know I’m a big fan of the BEM Syntax. If you haven’t heard of it, it’s basically a way to name your CSS classes in a way that makes sense and gives everybody involved with writing CSS for the site some knowledge of the structure. It really helps to write modular CSS and makes it easy to understand the code even if you get into a project later on.

BEM stands for Block Element Modifier. Here is an example to get you started:

.nav {
    // This is the BLOCK
    margin-bottom: 20px;
}

.nav__item {
    // This is the ELEMENT
    color: #000;
}

.nav__item--active {
    // this is the MODIFIER
    color: #1193e5;
}

Some people don’t like how the notation looks, but I assure you it works really well and even some people I first had to convince are totally stoked now.
Now let’s look at Sass 3.3 and what it has to offer.

With Sass you can use & to reference the selector which is already in place if you want to nest code. Just like this:

.nav {
    margin-bottom: 20px;

    & a {
        color: #000;
    }
}

This compiles to the following CSS:

.nav {
    margin-bottom: 20px;
}

.nav a {
    color: #000;
}

That’s pretty nice and straightforward and helps a lot in authoring CSS. With Sass 3.3 it gets even better if you are a BEM guy or gal. Now you can write our first example like this and get the exact same CSS output only that your Sass looks cleaner and you have less to write:

.nav {
    // This is the BLOCK
    margin-bottom: 20px;

    &__item {
        // This is the ELEMENT
        color: #000;
       
        &--active {
            // this is the MODIFIER
            color: #1193e5;
        }
    }
}

The CSS output looks as follows:

.nav {
    margin-bottom: 20px;
}
.nav__item {
    color: #000;
}
.nav__item--active {
    color: #1193e5;
}

I haven’t used that in production myself yet, but I will as soon as possible because I think it’s great. But I can imagine that if one would nest to deep it can get a little confusing. But the good thing is, just because you use it in one place doesn’t mean you have to use it every time. Nevertheless, make sure you Sass follows some kind of style guide.

Now if you ask yourself if you have Sass 3.3 installed you can check this by typing

$ sass -v

into you console of choice. If you are not on 3.3 you can update with

$ sudo gem install sass

After installing check if everything went well with

$ sass -v

As of writing this post Sass is at Version 3.3.4 (Maptastic Maple).

If you have any questions or suggestions, feel free to send me a tweet at @_martinwolf or write an email at martin@visuellegedanken.de

Hope this article helps some of you. Have a nice day!

Schreibe einen Kommentar

Deine E-Mail-Adresse wird nicht veröffentlicht. Erforderliche Felder sind mit * markiert.