🎨 bss
A simpler way to do CSS in Javascript directly on the elements you're styling.
bss
allows you to write your styles directly on the element where they matter using plenty of fun constructors.
Any group of definitions are resolved once one of the following properties are accessed / called
Installation
Using npm
npm install bss -S
Require from CDN
<script src="https://unpkg.com/bss"></script>
Or download and include - download bss.js
Example usage
Here's a quick example of using bss together with mithril - see the example live here
import b from 'bss'
import m from 'mithril'
let on = true
m.mount(document.body, {
view: vnode => m('h1' + b.bc('red').c('white').fs(32).ta('center'), {
style: b.bc(on && 'green').style,
onclick: () => on = !on
}, 'Hello world')
})
Creates the following in the dom, which toggles the style attribute on click.
<style>
.bdp4f3o1 {
background-color: red;
color: white;
font-size: 32px;
}
</style>
<body>
<h1 class="bdp4f3o1" style="background:green;">Hello world</h1>
</body>
Ways of writing CSS
In the spirit of Javscript - bss
Allows you to write the same thing in many different ways.
CSS Strings
b`
background-color: black;
text-align: center;
`
.$hover(`
background-color: red;
`)
Lean Strings
b`
background-color black
text-align center
`
.$hover`
background-color red
`
JS Objects
b({
backgroundColor: 'black',
textAlign: 'center',
':hover': {
backgroundColor: 'red'
}
})
Functions
b.backgroundColor('black')
.textAlign('center')
.$hover(
b.backgroundColor('red')
)
Output
.class
The .class
getter closes the current style description, creates a class name, adds the styles to a stylesheet in <head>
and returns the class name
b.textAlign('center').class
.style
The .style
getter also closes the current style description and return a JS object with the styles
b.textAlign('center').style
valueOf()
.valueOf()
will be called if b is used like 'div' + b
because javascript casts automatically using .valueOf()
.
Casting b
to a string will call .class
and prepend a period for easy use in vdom libraries.
'div' + b.textAlign('center')
You can also override .valueOf
if you set classNames instead of selectors
b.valueOf = function() { return this.class + ' ' }
`<div class="${ b.textAlign('center') }`"></div>` // Returns eg. <div class="bdp4f3o1"></div>
Short property names
Short property names can also be used and are the acronyms of full css properties with collisions handpicked by popularity
b.bc('black')
.ta('center')
.$hover(
b.bc('red')
)
.helper
Define your own helpers to work in a fashion similar to tachyons, or simply to make your life easier.
Tachyon style helpers
b.f1.p1
b.helper('f1', b.fontSize('3rem'))
b.helper('p1', b.padding('0.25rem'))
b.helper({
f1: b.fontSize('3rem'),
p1: b.padding('0.25rem')
})
Helpers can also take values like this:
b.size('100%').align('center')
b.helper('size', (width, height) =>
b.width(width).height(height || width)
)
b.helper('align', (x, y) =>
b.display('flex').justifyContent(x).alignItems(y || x)
)
They can even be easy to use media query groupers like this:
b.desktop(
b.fontSize(128)
)
b.desktop(`
fs 128
`)
b.helper('desktop', style => b.$media('(min-width:801px)', style))
Pixel values and Numbers
Properties accepting pixel values will automatically have px
added if a number type is passed.
b.fontSize(32) // font-size: 32px;
b.width(200) // width: 200px;
.$hover
:pseudo selectors
All of the different css pseudo selectors normally used with a colon :
is added with the dollor $
for ease of use in js.
b(`
color: red;
`).$hover(`
color: blue;
`)
b.color('red').$hover(b.color('blue'))
.$nest
nested selectors
Targeting nested children is sometimes useful, and is done by using $nest
and supplying the first argument with a regular child css selector, and then supply styling as the second argument for that selector.
b.color('red').$nest('li', b.color('blue'))
b.color('red').$nest(':hover li', b.color('blue'))
b.color('red').$nest('> &', b.margin(10))
&
is a placeholder for the generated class like in sass/less
.
Once you use &
in $nest
you take full responsibility of adding the generated class in the correct places to avoid creating global selectors.
One case where this could happen is if using the comma seperator to make multiple selectores, like doing $nest('th &, tr', ...)
. This would create a global tr
style. To do this right the code would need to be $nest('th &, tr &, ...)
.
Normally bss handles this for you such that $nest('th, tr', ...)
will be scoped locally, but using &
overrides this behavior.
.$media
@media queries
b.color('red').$media('(max-width: 600px)', b.color('blue'))
.$keyframes
@keyframes
Animation in CSS is usually a mixture of transition
and animation / @keyframes
. Transition
is handled as usual css properties by bss
, but @keyframes
are a bit different.
Creating a keyframe animation is done using b.$keyframes
and will return a generated name for the animation specified.
const fadeIn = b.$keyframes({
from: b.o(0).style,
to: b.o(1).style
})
b.animation(fadeIn + ' 1s')
.$animate
Often it might not be necessary to consider the animation name so a built in helper method called $animate
comes in handy. It takes a regular animation shorthand value as the first argument, excluding the animation name. The second parameter is the animation definition itself.
b.$animate('1s linear', {
from: b.o(0).style,
to: b.o(1).style
})
.css
A way to add regular css properties to a selector and prepend to the generated stylesheet
b.css('html', b.boxSizing('border-box'))
b.css('*, *:before, *:after', b.boxSizing('inherit'))
.setDebug
Since chrome dev tools doesn't allow changing styles applied using CSSOM you can activate debugging mode which doesn't apply the styles using CSSOM.
b.setDebug(true)
The only caveat here is that animations and applied styles can result in small quicks like blinking fonts and styles.
Specificity
To enhance developer expectations bss uses double class names for regular definitions to give higher specificity than nested items, which might have rules added from regular css, or from $nest
. To support this $nest
will not increase specificity by only adding the class name once.
Browser support
bss
is tested and works in ie9+ and the other major browsers.
TODO - Create browser support table
Prefixes
When using bss
in the browser it automatically adds only the necessary prefixes, so you can go ahead and use the raw property and expect it to work in browsers that only has the prefixed version.
Prefixes for css property values like linear-gradient
are not supported yet.
Server support
TODO - If using it on the server you can specify the prefixes that you'd like to be generated when generating the css.