CSS Builder • minicss

The goal of minicss is to be able to programatically create CSS styles and style sheets from within R.

minicss objects and output are compabile with Shiny (see the vignette)

Overview

minicss is a collection of R6 objects a user creates and encapsulates within one other to build CSS style sheets

Need to build…	R6 object	alternate initialisation
CSS Properties		`css_prop`
CSS Selectors	`Selector$new()`	`css_sel()`
KeyFrames	`Keyframe$new()`	`css_keyframe()`
	`Keyframes$new()`	`css_keyframes()`
CSS Styles	`Style$new()`	`css_style()`
CSS Style Sheets	`StyleSheet$new()`	`css_stylesheet()`

Quick examples

CSS Entity	code	result
Properties	`css_prop$'font-family'$cursive`	`font-family: cursive;`
	`css_prop$'animation-delay'$set(12)`	`animation-delay: 12;`
Selectors	`css_sel('#cindy')$child_of('#carol')`	`#carol > #cindy`
Inline Styles	`css_style(colour='red')$update(margin=0)`	`color: red; margin: 0;`
CSS Styles	`css_style(".red", colour='red', width='100%')`	`.red { color: red; width: 100% }`
	`css_style(".big", css_prop$'font-size'$set('12px'))`	`.big { font-size: 12px; }`
Style Sheets	`css_stylesheet(style1, style2)`	`.style1 {color:red;} .style2{color:blue;}`

Installation

You can install the development version from GitHub with:

# install.packages("devtools")
devtools::install_github("coolbutuseless/minicss")

Future

The CSS specification is a bit wart-y, so there are plenty of weird cases that need to be explicitly handled. Some of these cases are currently handled by minicss, and I’ll add others as they’re needed.

Vignettes

Example: All-in-one example

#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# Build some selectors
#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
sel1 <- Selector$new('h1')$class('demo')
sel2 <- css_sel("h2")$class('highlight')

#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# Build some keyframes for animating elements
#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
kf1 <- Keyframe$new('from', color = '#123456')
kf2 <- css_keyframe('to', color = '#1289ae')$translateX(10, 'px')
keyframes  <- Keyframes$new("pulser", kf1, kf2)

#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# Build some styles
#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
style1 <- Style$new(
  sel1, 
  css_prop$animation(name = 'pulser', duration = 0.8, direction = 'alternate')
)
style2 <- Style$new('.mini', background_color = 'green')
style3 <- Style$new(sel2, css_prop$`text-decoration`$underline)

#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# Create a style sheet
#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
stylesheet <- css_stylesheet(style1, style2, style3, keyframes)

#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# Change my mind about the background colour of 'style2'
#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
style2$update(background_colour = '#a0a0ff')

#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# Create an inline style
#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
inline_style <- Style$new(border = "1px solid #123456")$
  update(width = "50%", padding = '10px')$
  as_inline()

#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# Insert the stylesheet in an example HTML document
#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
html <- glue::glue("
<html>
<head>
  <title>Example</title>
  <style>
{stylesheet}
  </style>
</head>
<body>
<div style='{inline_style}'>
<h1 class = 'demo'> Hello #Rstats</h1>
<h2 class='highlight'> A minicss demo! </h2>
This is an example of using <span class='mini'>minicss</span> to manipulate CSS.
</div>
</body>
</html>")

minicss