串

Styling in ClojureScript

Native ClojureScript styling solution

Shorthand syntax based on standard CSS

Co-locates all styles at the element level

Compile-time macros generate static css

Supports media-queries, psuedos, and combo selectors

Leverages CSS variables for runtime dynamics

Composable, user-defined shared classes

Ships with a small handful of useful utility classes

Includes a default industry-standard breakpoint scale

Predefined scales for typography, widths, & more

Auto-generated selectors to avoid pontential collisions

Robust and flexible selector prefixing options

Enhanced debugging via metadata

Detailed warnings for the terminal and browser

Framework & build-tool agnostic

Index

Setup and usage
Syntax
Shared styles
Media queries
Pseudos and combo selectors
Using scales
Injecting stylesheets
Adding font resources
Element attributes
Helpful metadata
Configuration options
Prefixing options
Runtime injection
Useful warnings
Usage with build tools
Roadmap
Development
License

Setup and Usage

For a well commented, feature-complete minimal project template, please see kushi-quickstart.

Syntax

Styles are co-located at the element level.
Wrap your attributes with the kushi.core/sx macro:

(defn my-component []
 [:div
  (sx {:id    :my-id
       :style {:color      :red
               :text-align :center
               :font-size  :18px}})])

Kushi promotes a simple shorthand grammer which shadows standard CSS.
The above example would be written like this:

(defn my-component []
 [:div
  (sx {:id    :my-id
       :style {:c  :red
               :ta :c
               :fs :18px}})])

If you want to go faster, write your styles as tokenized keywords.
This is similar to Tachyons/Tailwind, but much more helpful in learning actual CSS.

(defn my-component []
 [:div
  (sx :c--red
      :ta--c
      :fs--18px
      {:id :my-id})])

In all three examples above, the sx macro would return the following attribute map with an auto-generated value for the class attribute:

{:class "_c7338"
 :id    :my-id}

When your build finishes, the following css will be written to disk:

 ._c7338 { color: red; text-align: center; font-size: 18px; }

If you need or want to define your own classnames, you can leverage kushi's flexible and robust prefixing options:

;; Assuming you have a global prefix set with a value of "_foo_",
;; kushi will combine it with a local supplied :ident value

(defn my-component []
 [:div
  (sx :c--red
      :ta--c
      :fs--18px
      {:ident :bar
       :id    :myid})])

The above example would generate the following attribute map:

{:class "_foo_bar"
 :id    :myid}

And the following css will be written to disk:

 ._foo_bar { color: red; text-align: center; font-size: 18px; }

In summary, the kushi.core/sx is a macro that returns an attribute map which contains the following:

• A class property containing the correct auto-generated/prefixed classnames.
• If necessary, a style property containing the correct auto-generated css variable names.
• All the other attributes you specify in your attributes map (supplied as an optional last arg to sx).
• A dev-build-only data-cjs attribute to help with browser-based debugging.
  See Using metadata.

All your css is written to a static file, via a build hook for the :compile-finish stage (or similar depending on build tool). For zippy previews when developing, styles are injected at runtime. You can optionally disable writing styles to disk and enable producton builds to inject styles at runtime.

Styles as Keywords

Kushi aims to provide the same benefits as Tachyons/Tailwind (styling expressed as a list of tokens co-located at the element level) while minimizing some of the common downsides (learning and using a whole new abstraction layer on top of standard css).

You can provide style rules as tokenized keywords.
Keywords containing -- represent a css prop and value pair (split on --).

:color--red

Some more examples, using kushi's optional shorthand grammer.

:c--red   ; => :color--red
:ai--c    ; => :align-items--center
:ai--e    ; => :align-items--end
:ta--r    ; => :text-align--right
:fs--18px ; => :font-size--18px
:d--b     ; => :display--block
:d--f     ; => :display--flex
:bgs--50% ; => :background-size--50%

This shorthand grammer is available for the most commonly used props:

:ai  ; align-items
:b   ; border
:bb  ; border-bottom
:bc  ; border-color
:bg  ; background
:bgc ; background-color
:bgi ; background-image
:bgp ; background-position
:bgr ; background-repeat
:bgs ; background-size
:bl  ; border-left
:br  ; border-right
:bs  ; border-style
:bt  ; border-top
:bw  ; border-width
:c   ; color
:d   ; display
:ff  ; font-family
:fs  ; font-size
:fv  ; font-variant
:fw  ; font-weight
:h   ; height
:jc  ; justify-content
:ji  ; justify-items
:lh  ; line-height
:m   ; margin
:mb  ; margin-bottom
:ml  ; margin-left
:mr  ; margin-right
:mt  ; margin-top
:o   ; opacity
:p   ; padding
:pb  ; padding-bottom
:pl  ; padding-left
:pr  ; padding-right
:pt  ; padding-top
:ta  ; text-align
:td  ; text-decoration
:tdc ; text-decoration-color
:tdl ; text-decoration-line
:tds ; text-decoration-style
:tdt ; text-decoration-thickness
:tt  ; text-transform
:va  ; vertical-align
:v   ; visibility
:w   ; width
:ws  ; white-space
:zi  ; z-index

Shorthand grammer extends to cover enumerated values:

;; text-transform
:tt--u   ; text-transform--uppercase
:tt--l   ; text-transform--lowercase
:tt--c   ; text-transform--capitalize
:tt--fw  ; text-transform--full-width

;; background-repeat
:bgr--nr ; background-repeat--no-repeat
:bgr--rx ; background-repeat--repeat-x
:bgr--ry ; background-repeat--repeat-y
:bgr--r  ; background-repeat--round
:bgr--s  ; background-repeat--space

;; align-items
:ai--c   ; align-items--center
:ai--fs  ; align-items--flex-start
:ai--fe  ; align-items--flex-end
:ai--n   ; align-items--normal
:ai--s   ; align-items--start
:ai--e   ; align-items--end
:ai--b   ; align-items--baseline

For complete info on available enumurated values view the source here.

Expressing dynamic values

Sometimes you will need to use variables or css syntax (for the property value) that is inherently complex. In these cases, you cannot use tokenized keywords and must locate your styling in the :style entry of the attributes map:

Most commonly, when using dynamic values:

(sx {:style {:color my-color})

When a string is desired, or necessary:

(sx {:style {:before:content "\"*\""
             :width "calc((100vw / 3) + 12px)"}})

When using kushi.core/cssfn to construct a value:

(sx {:style {:transform (cssfn :translateY :-100px)}}])

Using cssfn

As seen in the example above, you can use kushi.core/cssfn to contruct values.

(sx {:style {:c (cssfn :rgba 0 200 100 0.4)}})

;; The above example is equivalent to:
(sx {:style {:color "rgba(0, 200, 100, 0.4)"})

cssfn will only work when used inside a call to the sx macro.

CSS Shorthand Properties

CSS shorthand properties are properties that let you set the values of multiple other CSS properties simultaneously. You can write them like this:

;; Kushi-style, tokenized kw
(sx :b--1px:solid:black)

;; Kushi-style
(sx {:style {:b :1px:solid:black}})

;; Garden-style
(sx {:style {:b [[:1px :solid :black]]}})

;; With string
(sx [:b "1px solid black"])

The above examples will resolve to the following css declaration:

border: 1px solid black;

Future support is planned for dynamic values nested in garden-style double vectors and css values construction method such as kushi.core/cssfn or cljs.core/str.
In the meantime, if you would like to incorporate a dynamic value into a css shorthand property, you can do it like this:

;; Write the shorthand with a "default" value that subsequently
;; gets overridden with a dynamic value on the specific property.
(sx {:style {:b :1px:solid:black
             :bc mycolor}}

;; Alternatively, this would work:
(let [myborder (str "1px solid " mycolor)]
   (sx {:style {:b myborder})

CSS Value Lists

Sometimes multiple css values are seperated by commas to indicate they are ordered, or that there are ordered alternatives. With kushi, you can write them like this:

(sx :ff--FiraCodeRegular|Consolas|monospace)

The above will resolve to the following css declaration:

font-family: FiraCodeRegular, Consolas, monospace;

The example below uses a list of css shorthand values in order to render multiple text-shadows in different colors:

(sx :text-shadow--5px:5px:10px:red|-5px:-5px:10px:blue)

The above will resolve to the following css declaration:

text-shadow: 5px 5px 10px red, -5px -5px 10px blue;

Shared Styles

The kushi.core/defclass macro makes it easy to create shared styles.
These must be defined in a dedicated namespace, or set of dedicated namespaces, and required once in your core or main ns.

The example below will generate a data-representation of the css rule-set.
This data is added to a register (an atom that exists in the build state).
This css class is only written to disk if a component references it.

(ns myapp.shared-styles
  (:require
   [kushi.core :refer (defclass)]))

(defclass headline
  :.absolute
  :top--0
  :left--0
  :b--1px:solid:black
  :fs--200px
  :tt--u
  :font-style--italic
  :mix-blend-mode--darken)

By authoring your shared styles in a dedicated ns (or namespaces), you only need to require once in your main or core ns, and all the styles from that ns will be available globally.

(ns myapp.core
  (:require
   [kushi.core :refer (sx)]
   [myapp.shared-styles]))

  (defn my-headline [text]
    [:h1 (sx :.headline) text])

;; The above call to the sx macro will return the following attribute map:
;; {:class "_s77920__headline"}

;; When your build finishes, the following css would be written to disk:
;; ._s77920__headline {
;;     position: absolute;
;;     top: 0px;
;;     left: 0px;
;;     border: 1px solid black;
;;     font-size: 200px;
;;     font-style: italic;
;;     text-transform: uppercase;
;;     mix-blend-mode: darken;
;; }

As arguments to sx, classes are distinguished from other prop-styles by using a keyword beginning with a ., e.g. :.headline, as in the example above.

You may have noticed that the defclass example above mixes-in :.absolute.
With defclass, you can mix-in any other defined classes.
The :.absolute class is one of several predefined classes that ships with kushi.

The full list of predefined classes:

;; positioning
:.absolute
:.absolute-centered
:.absolute-fill
:.relative
:.fixed
:.fixed-fill

;; background-images
:.bgi-contain
:.bgi-cover
:.debug-grid
:.debug-grid-16
:.debug-grid-16-solid
:.debug-grid-8-solid

;; flex layouts
:.flex-col-c
:.flex-col-fe
:.flex-col-fs
:.flex-col-sa
:.flex-col-sb
:.flex-col-se
:.flex-row-c
:.flex-row-fe
:.flex-row-fs
:.flex-row-sa
:.flex-row-sb
:.flex-row-se

;; borders & outlines
:.bordered
:.outlined

;; type styling
:.sans
:.italic
:.oblique

;; type weight
:.thin
:.extra-light
:.light
:.regular
:.medium
:.semi-bold
:.bold
:.extra-bold
:.heavy

;; psuedo-element helper
:.content-blank

Detailed documentation on the above classes can be found here.

Applying Classes Conditionally

You can apply classes conditionally within the sx macro using the following constructs: if when cond if-let when-let if-not when-not, and case.

(defn link [opts]
 [:a
  (sx (when (:active? opts) :.active-link)
      :bb--1px:solid:black))
  "Go"])

;; Somewhere else in your code, calling above component

[link {:active? true}]
; => [:a {:class ["_kushi_active-link" "_j7338" ]}]

;; "_kushi_active-link" is the selector for your custom defclass.

The class to be returned cannot be nested.
For example, the following will not work:

;; This will NOT work.
(defn link [opts]
 [:a
  (sx (when (:active? opts)
        (if foo :.active-link :.some-other-class))
      :bb--1px:solid:black))
  "Go"])

Media Queries

;; Specify the font-size of an <h1> element across breakpoints
[:h1
 (sx :fs--1.25rem
     :md:fs--1.5rem
     :lg:fs--1.75rem
     :xl:fs--2rem)]

As in the example above, you can use preceding modifiers to set different values for a property at different breakpoints.

Kushi ships with the following, industry-standard, mobile-first breakpoint scale:

[:sm {:min-width :640px}
 :md {:min-width :768px}
 :lg {:min-width :1024px}
 :xl {:min-width :1280px}
 :2xl {:min-width :1536px}]

Both the names and values can be customized via supplying a kwargs vector as the :media entry in your kushi.edn config file. Becuase CSS Media Queries must be explicity ordered, this scale must be written as a vector of kwargs. See Configuration Options.

Below is an example of a scale that is desktop-first and uses different names.
Note that in the case of desktop-first(max-width), the order is reversed (relative to mobile-first / min-width).

[:desktop {:max-width :1280px}
 :tablet {:max-width :1024px}
 :mobile {:max-width :768px}
 :small {:max-width :640px}]

Any media-query modifier that you use must correspond to a key in the breakpoint map.

When "stacking" other modifiers (such as psuedo-classes) in front of css props, the media queries must always come first.

Pseudos and Combo Selectors

Pseudo-classes, pseudo-elements, and combo selectors are available via modifiers:

(sx :hover:c--blue
    :>a:hover:c--red
    :~a:hover:c--blue
    :_a:hover:c--gold ; The "_" gets converted to " "
    :before:position--absolute
    :before:top--0
    :before:right--0
    :before:fw--bold
    {:style {:before:content "\"*\""
             "nth:child(2):c" :red}})

;; The `:before:content` and `nth:child(2)` in the above
;; example must both be expressed in the stylemap.

Defining Animations

kushi.core/defkeyframes macro makes it easy to define css keyframes.

;; This will twirl something on its y-axis
(defkeyframes y-axis-spinner
  [:0% {:transform (cssfn :rotateY :0deg)}]
  [:100% {:transform (cssfn :rotateY :360deg)}])


;; Somewhere in your component code...
[:div
 (sx :fs--32px
     :animation--y-axis-spinner:12s:linear:infinite)
 "Round & Round"]

Because names for css @keyframes definitions are used as-is in other style rules that reference the animation, kushi does not apply any auto-generated prefixing to @keyframes names in the generated css. If you are worried about potential collisions with your @keyframes definitions and some other 3rd party @keyframes definitions, you should give them a prefixed name when you define them:

(defkeyframes my-prefix__y-axis-spinner
 ...)

Using Scales

Kushi ships with two different predefined scaling systems, which provide a scale of values for width, font-size, padding, margin, and border-widths.

These two systems shadow the scales provided by Tachyons and Tailwindcss.

The Tacyons scale is available by default.
You can opt to instead use the Tailwind scale in your kushi.edn config file:

{...
 :scaling-system :tailwind
 ...}

To use values from these scales, supply a value affixed with an * to one of the applicable css properties:

(sx :w--1*
    :bw--2*
    :fs--3*
    :p--sm*
    :m--md*)

;; The above is equivalent to the following

(sx :width--1rem
    :border-width--.25rem
    :font-size--1.5rem
    :padding--.5rem
    :margin--1rem)

View all the scale values here.

Injecting Stylesheets

You can use kushi.core/inject-stylesheet to load css stylesheets.
The example below (typical use case), loads a stylesheet from Google Fonts.

;; The additional "preconnect" hints will improve Google Fonts performance.

(inject-stylesheet {:rel "preconnet"
                    :href "https://fonts.gstatic.com"
                    :cross-origin "anonymous"})

(inject-stylesheet {:rel "preconnet"
                    :href "https://fonts.googleapis.com"})

(inject-stylesheet {:rel "stylesheet"
                    :href "https://fonts.googleapis.com/css2?family=Inter:wght@900&display=swap"})

You can also use kushi.core/inject-stylesheet to inject a css reset stylesheet, or a third-party style library. This is more of an edge case, as you would typically just do this with a <link> in your index.html.
However, if your project uses a clj file to generate the contents of your <head> at build time, it may be handy to use this during development to inject new stylesheets without restarting your build.

(inject-stylesheet {:rel "stylesheet"
                    :href "css/my-global-styles.css"})

Adding Font Resources

You can use the kushi.core/add-font-face macro to load a local font from a file.
This will add an @font-face block to the css file generated by kushi.
The location of the font file must be a path, relative the location of the generated css file.
You could also use a remote url to load a hosted font file.

(add-font-face {:font-family "FiraCodeRegular"
                :font-weight "400"
                :font-style "normal"
                :src ["url(../fonts/FiraCode-Regular.woff)"]})

System Font Stack

You can use the kushi.core/add-system-font-stack macro to use a system font stack. This uses an efficient, @font-face-based approach introduced by Jonathan Neal.

; In your core namespace
(add-system-font-stack)

The example above would add a total of 8 @font-face definitions to your kushi css file. One normal and one italic for weights 300("light"), 400("regular"), 500("semi-bold"), and 700("bold"). Note that the name of the font-family kushi provides is system, not system-ui. This is for differentiation and to help avoid confusion.

@font-face {
  font-family: system;
  font-style: normal;
  font-weight: 300;
  src: local(".SFNS-Light"), local(".SFNSText-Light"), local(".HelveticaNeueDeskInterface-Light"), local(".LucidaGrandeUI"), local("Segoe UI Light"), local("Ubuntu Light"), local("Roboto-Light"), local("DroidSans"), local("Tahoma");
}
@font-face {
  font-family: system;
  font-style: italic;
  font-weight: 300;
  src: local(".SFNS-LightItalic"), local(".SFNSText-LightItalic"), local(".HelveticaNeueDeskInterface-Italic"), local(".LucidaGrandeUI"), local("Segoe UI Light Italic"), local("Ubuntu Light Italic"), local("Roboto-LightItalic"), local("DroidSans"), local("Tahoma");
}
/* + 6 more */

If you want to be more precise you can pass in only the weights you need. The example below would write a total of 4 @font-face rules to your kushi css file (normal and italic for both 300("light") & 700("bold")).

(add-system-font-stack 300 700)

Then you can use the system font stack like so:

[:div (sx :font-family--system)]

; Using kushi shorthand:
[:div (sx :ff--system)]

; An example using kushi syntax to specify multiple values for the css shorthand `font` property.
[:div (sx :font--italic:700:system)] ;

Helpful Metadata

Relative to using vanilla css or sass, kushi will obviate the need to write your styles in a separate location and/or language. In turn, you will not need to worry about keeping selector names in css files synced with classnames in your markup code.

With kushi, elements in the DOM will have auto-generated class names. As a result, it can become difficult to quickly comprehend the source location when looking at elements in a browser inspector (such as Chrome DevTool Elements panel).

During development builds, the sx macro will automatically attach a data-cljs attribute to the DOM element. The value of this is the file name, line number, and column number of the source.

(ns myapp.core
  (:require
   [kushi.core :refer (sx)]))

;; A component defined, for example, on line 170
(defn my-button [text]
  [:button
   (sx :c--white
       :bgi--none
       :bgc--blue
       :border-radius--5px
       :cursor--pointer)
     text])

You would see something like this in the browser console, when inspecting an element rendered from this function:

<div data-cljs="myapp.core.cljs:172:4" class="_h30702"">
  Button Text
</div>

If you would like to change the name of this attribute to something else (for example, data-foo), simply supply a :data-attr-name entry with a value of :data-foo in your kushi.edn config map.

Configuration Options

Various options are configurable via a required kushi.edn file.
This file must live in your project's root directory.

The only required entry in this map is :css-dir

{
 ;; REQUIRED.
 ;; Must be relative to proj root e.g "public/css" or "resources/public/css".
 :css-dir "public/css"
}

Below is a full map of all the options available:

{
 ;; REQUIRED.
 :css-dir "public/css"

 ;; Optional. Name of generated css file.
 ;; Defaults to "kushi.css".
 :css-filename "my-kushi-styles.css"

 ;; Optional. Narrow kushi compilation down to select namespaces.
 :select-ns [app.ui.foo app.ui.bar]
 ;; :select-ns [app.ui.*] ;; will target all namespaces under app.ui

 ;; Optionally prepend an ancestor element to selectors.
 ;; Useful for scoping.
 :ancestor :#my-target-div

 ;; Optional. If defined, AND an :ident value is supplied at
 ;; the `sx` call site, this will be used for classnames,
 ;; instead of auto-generated hash.
 :prefix "_my-prefix__"

 ;; Optional. If defined, this will be used as the prefix for
 ;; the classnames of shared styles (defined with defclass).
 ;; Defaults to "_kushi_"
 :defclass-prefix "_my-shared-class-prefix__"

 ;; Optional. If defined, this will be used as an attribute
 ;; name for attaching source file info to the rendered
 ;; element in the DOM (dev only).
 ;; Defaults to "data-cljs"
 :data-attr-name "data-foo"

 ;; Optionally defined your own breakpoint scale to override
 ;; kushi's default breakpoint scale.
 ;; This must be a vector of kwargs, not a map.
 :media [:2xl {:max-width :1536px}
         :xl {:max-width :1280px}
         :lg {:max-width :1024px}
         :md {:max-width :768px}
         :sm {:max-width :640px}]

 ;; Optional setting for using a map as the first argument
 ;; to the `kushi.core/sx` macro.
 :map-mode? false

 ;; Optional setting for printing-style of kushi compilation
 ;; info to the console running your build.
 ;; Defaults to :simple.
 :reporting-style :banner

 ;; Optional setting to silence the post-build report.
 :post-build-report?  false
}

Prefixing Options

If you would like to prefix your generated classes with something other than an auto-generated string, you can make use of several kushi-specific properties in the attribute map that you pass to sx. These keys and values are only used by the macro at compile time and are removed in the attribute map that is returned by sx.

The most common use case for this would be setting a global :prefix value, and then providing an :ident value (in the attr map) to some or all of your calls to sx. If you do this on a project-wide basis, you will need to make sure that your all your :ident values (or combos of :ancestor and :ident) are globally unique. The (kushi) compiler will warn you if you try to do this.

;; In your kushi.edn map ...
{:prefix :_mypfx__}

;; In one of your component namespaces ...
[:div
 (sx :c--red
     {:ident :my-el})]

;; The above example will return the following attribute map:
;; {:class "_mypfx__my-el"}

;; And will write the following rule to the css file:
;; ._mypfx__my-el {
;;    color: red;
;;}

Note that using an :ident property will only affect the selector name if you also have a value set for :prefix in your kushi.edn config. Otherwise, the :ident property will be ignored and you will just get an auto-generated selector. If you want to use a custom prefix a la carte, you can supply both :prefix and :ident locally to the attr map that you are passing to sx.

You can also use an :ancestor and/or :element prop for further selector specicifity. The value of :ancestor has to match the id or class of one of the element's ancestors. The value of :element needs to be the same as the element that sx is being called within.

[:div
 (sx :c--red
     {:ident :my-el
      :ancestor :#myapp
      :element :div})]

;; The above would instead result the following css:
;; #myapp div._mypfx__my-el {color: red;}

Another example:

(defn my-button [text]
  [:button
   (sx :c--white
       :bgi--none
       :bgc--blue
       :border-radius--5px
       :cursor--pointer
       {:on-click #(prn "clicked!")
        :class [:my-other-class :some-other-class]
        :name :my-button

        ;; Prefix for selector construction.
        ;; Overrides a global :prefix, if set.
        :prefix "_foo_"

        ;; If :ident is supplied, and you also set a global :prefix,
        ;; (or set :prefix in this map) your selector will be
        ;; constructed using both.
        ;; => ._foo_bar
        :ident :bar

        ;; If :element is supplied, it will be put in front
        ;; of your selector for more specicifity.
        ;; => `button._foo_bar`
        :element :button

        ;; Ancestor selector for selector construction.
        ;; Overrides a global :ancestor, if set.
        ;; => #baz button._foo_bar
        :ancestor :#baz
        })
     text])

Runtime Injection

For instantaneous previews when developing, all styling from sx and defclass calls are injected dynamically into the following 2 tags that are required to be in your index.html :

<style type="text/css" id="_kushi-rules_shared_"></style>
<style type="text/css" id="_kushi-rules_"></style>

See the kushi-quickstart template for an example of this setup.

You can enable this for release builds:

;; Add this to config map in your kushi.edn file

;; {...
    :runtime-injection? true
;;  ...}

to your `kushi.edn`.

Useful Warnings

Given the following:

(sx :.relative
    :ta--center
    "badstring"
    :.sans
    :p--10px
    12
    :fs--18px
    :c--#efefef)

You will receive warnings about invalid args in the terminal:

And also in your browser's dev console:

The browser console warning will provide you with file and line info.

Usage with Build Tools

shadow-cljs

See the kushi-quickstart template for a detailed example of using Kushi in a shadow-cljs project.

Roadmap

...more info coming soon.

Development

...more info coming soon.

License

Copyright © 2021 Jeremiah Coyle

Distributed under the EPL License. See LICENSE.