Bowhead v0.1.8

What? permalink

Bowhead is a small SCSS framework on which to implement your design tokens, spitting out CSS Variables with optional fallbacks.

Why? permalink

Implementing a design system or even just a series of simple design tokens can come with some unpredictable mental overhead. Bowhead aims to reduce that mental overhead by abstracting the specifics of design tokens into human-sensible formats and nomenclature.

This has a positive effect that ranges from giving the colours in your design system fun and memorable names, to the time and effort saved when communicating about these colours with collaborators without getting bogged down by details, because let’s be real: you don’t want or need to memorise the six-character hex value for all your colours, nor does anyone else! Now imagine that scenario when applied to multiple times more design tokens.

Installation permalink

Yoink it from npm:

npm install @chrisburnell/bowhead

You can also just download it directly from GitHub:
https://github.com/chrisburnell/bowhead/archive/master.zip

Usage permalink

There are three main moving parts to this set-up, and an optional fourth:

1. $bowhead-tokens
2. $bowhead-show-fallback
3. $bowhead-generate
4. $bowhead-property-map

01. Tokens

$bowhead-tokens expects an SCSS map of "types" of tokens. These types could be a measure, color, opacity, z-index, etc.

$bowhead-tokens: (
    measure: (
        small:  0.5rem,
        medium:   1rem,
        large:    2rem,
    ),
    color: (
        brick:    #b22222,
        plankton: #3cb371,
        desert:   #d2b48c
    ),
    opacity: (
        alpha: 0.8,
        beta:  0.5,
        gamma: 0.2
    ),
    z-index: (
        below:  -1,
        root:    0,
        default: 1,
        above:   2
    )
);

02. Show Fallback Value

$bowhead-show-fallback is either true (default) or false and determines whether or not Bowhead should print fallback values for browsers that do not support CSS Variables.

$bowhead-show-fallback: true;

body {
    color: #b22222;
    color: var(--color-desert);
}

$bowhead-show-fallback: false;

body {
    color: var(--color-desert);
}

03. Generating CSS Variables

$bowhead-generate is either true (default) or false and determines whether or not Bowhead should print CSS Variables for you, like so:

:root {
    --measure-small: 0.5rem;
    --measure-medium: 1rem;
    --measure-large: 2rem;
    --color-brick: #b22222;
    --color-plankton: #3cb371;
    --color-desert: #d2b48c;
    --opacity-alpha: 0.8;
    --opacity-beta: 0.5;
    --opacity-gamma: 0.2;
    --z-index-below: -1;
    --z-index-root: 0;
    --z-index-default: 1;
    --z-index-above: 2;
}

04. Property Map (optional)

$bowhead-property-map is another map that contains mappings from CSS properties (padding-left, border-bottom-right-radius, etc.) to our defined design token "types" (measure, color, etc.), i.e.

(
    width: measure,
    min-width: measure,
    max-width: measure,
    height: measure,
    min-height: measure,
    max-height: measure,
    ...
)

If you wish, you can create new mappings or overwrite existing defaults by defining your own property map, e.g.

$bowhead-property-map: (
    vertical-align: alignments
);

Where alignments would be one of your design token "types", e.g.

$bowhead-tokens: (
    alignments: (
        default: baseline,
        alternate: middle
    ),
    ...
);

Bowhead will merge your defined map into its own defaults automatically!

Then you’ll have to include Bowhead in your SCSS somehow. You could use Webpack or something like that, or if you’re using npm, the below code snippet should suffice.

Take note that you need to define any of your Bowhead variables ($bowhead-tokens, $bowhead-show-fallback, $bowhead-generate(, $bowhead-property-map)) before importing Bowhead into your SCSS!

$bowhead-tokens: (
    ...
);
$bowhead-show-fallback: true;
$bowhead-generate: true;
$bowhead-property-map: (
    ...
);

@import "node_modules/@chrisburnell/bowhead/bowhead";

Finally, you can use either Bowhead's @v function, @v mixin, both, or just the CSS Variables it can spit out. However you use it is totally up to you! :)

.thing {
    @include v(background-color, desert);
    @include v(color, brick);
    border: v(measure, small) solid v(color, plankton);
    padding: v(measure, medium) v(measure, large);
    @include v(z-index, above);
    opacity: var(--opacity-alpha);
    // 1. if you just want the raw value, this is not really recommended:
    text-decoration-color: map-get(map-get($bowhead-tokens, "color"), "brick");
    // 2. this does the same for you:
    text-decoration-color: v(color, brick, true);
    // 3. so does this, although it includes the CSS Variable too:
    @include v(text-decoration-color, brick, true);
}

will generate…

.thing {
    background-color: #d2b48c;
    background-color: var(--color-desert);
    color: #b22222;
    color: var(--color-brick);
    border: var(--measure-small) solid var(--color-plankton);
    padding: var(--measure-medium) var(--measure-large);
    z-index: 2;
    z-index: var(--z-index-above);
    opacity: var(--opacity-alpha);
    /* 1 */
    text-decoration-color: #b22222;
    /* 2 */
    text-decoration-color: #b22222;
    /* 3 */
    text-decoration-color: #b22222;
    text-decoration-color: var(--color-brick);
}