np90 v0.25.1

NP90

I just needed a bit of sugar upon my CSS.

NP90 builds upon P90 for Node projects. It adds support for:

• Processing .p90 files into .css files.
• Svelte preprocessing.

A minimalist value replacement processor for CSS. Let plain JavaScript handle preprocessing logic, not a CSS mutant.

Honestly, this tool is straight up optimised for my tastes. The design trade-offs lean towards simplicity, readability, and flexibility more than writability. Complexity of mapping values is almost entirely in the user's court.

P90 scans CSS for P90 tokens which are substituted with user defined values. It's really just an enhanced string.replace.

Import for Svelte

{
	"devDependencies": {
		"np90": "v0.25.1"
	}
}

p90-styles.js

Rename, move, and reorganise as you see fit. See P90 for the value mapping rules.

I've made so many changes to this example that it probably contains a few errors. The rewrite is in my TODO list so will probably never get done.

// ./src/p90-styles.js
import { rgbsToColors, themeVariables, colorSchemes } from 'np90/util'

const rgbs = {
	burly_wood: [222, 184, 135],
	ice_cream: [250, 250, 250],
	very_light_sky_blue: [231, 245, 255],
	jet_blue: [30, 85, 175],
	dark_navy_grey: [5, 10, 60],
	very_dark_navy: [5, 10, 35],
}

const colors = rgbsToColors(rgbs)

const themes = {
	// P90 doesn't care what the theme names are but browsers do!
	light: {
		base: colors.ice_cream,
		text: colors.dark_navy_grey,
		strong: colors.jet_blue,
	},
	dark: {
		base: colors.very_dark_navy,
		text: colors.very_light_sky_blue,
		strong: colors.burly_wood,
	},
}

export default {
	rgb: rgbs,
	color: colors,

	color_schemes: colorSchemes(themes),
	theme: themeVariables(themes),

	// The function is called for each instance.
	// There is no caching unless you implement it.
	colorWithAlpha: (color, alpha) => {
		const rgb = rgbs[color]

		// Function arguments are always strings.
		// Parse them as you see fit.
		const a = parseFloat(alpha)

		const result = [...rgb]

		if (rgb.length === 3) {
			result.push(a)
		} else {
			result[3] = a
		}

		return result
	},

	font: {
		family: {
			sans_serif: ['sans-serif', 'Helvetica', 'Arial', 'Verdana'],
		},
		size: {
			// Constructed using utopia.fyi... Could these be constructed in code?
			md: 'clamp(1.06rem, calc(0.98rem + 0.39vw), 1.38rem)',
			lg: 'clamp(1.25rem, calc(1.19rem + 0.31vw), 1.5rem)',
			xl: 'clamp(1.5rem, calc(1.41rem + 0.47vw), 1.88rem)',
		},
	},

	screen: {
		larger_devices: `(min-width: 900px)`,
	},
}

svelte.config.js

Add np90 to the preprocess array in your svelte.config.js. Import and pass your styles to it.

// svelte.config.js
import np90 from 'np90/svelte'
import styles from './src/p90-styles.js'

export default {
  ...,
  preprocess: [np90(styles)],
  ...,
}

// svelte.config.js
import np90 from 'np90/svelte'
import styles from './src/p90-styles.js'

// Config and options with their defaults.
const config = {
	stdout: console.log,
	stderr: console.error,

	// If true, errors will be thrown immediately ending the processing.
	// Default is off beccause Svelte and various CSS checkers will usually tell
	// you where the errors are. They're better at it too.
	throwOnError: false,

	// Prints file name and token info when an error is encountered.
	printErrors: true,

	// List of accepted lang attibute values.
	// import { defaultMimeTypes } from 'p90'
	mimeTypes: [
		'', // Undefined, null, or empty lang attribute.
		'text/css',
		'text/p90',
	],
}

export default {
  ...,
  preprocess: [np90(styles, config)],
  ...,
}

+layout.svelte

<slot />

<style>
	/* prettier-ignore */
	$color_schemes

	:global(body) {
		background: $theme.base;
		color: $theme.text;
		font-family: $font.family.sans_serif;
		font-size: $font.size.md;
	}
</style>

+page.svelte

<page>
	<h1>A Bohemian quest for simplicity</h1>

	<p>
		It took me about an hour to learn and write my first Svelte CSS
		pre-processor after deciding existing tooling was too obese for my needs.
		Refactoring reduced my solution to about 20 lines of code. It simply
		substituted named values like `$green` with whatever I configured `rgb(10,
		240, 10)`. I moved it to it's own repository, enhanced it a little, and
		added a handful of utility functions for common use cases.
	</p>

	<p>
		It was so simple that I started wondering why we drag around a plethora of
		CSS like languages with needless diabolical syntax. Because it's easier to
		use a cumbersome tool you know than invest effort in adapting to the new
		environment.
	</p>

	<p>
		And why do slow complex transpiling when fast and simple value substitution
		can do the job. Let JavaScript handle logic, not a CSS mutant. That's what
		JavaScript is designed to do. You know, making use of languages we already
		know and hate.
	</p>
</page>

<style>
	h1 {
		color: $theme.strong;
		font-size: $font.size.lg;

		/* You don't have to put single or double quotes around arguments. */
		/* But it helps */
		background-color: $colorWithAlpha('burly_wood', 0.2);
	}

	@media $screen.larger_devices {
		h1 {
			font-size: $font.size.xl;
		}
	}
</style>