Package 'linne'

Title: Convenient 'CSS' for 'Shiny' and 'Rmarkdown'
Description: Conveniently generate 'CSS' from R to use in 'Shiny', 'Rmarkdown', 'htmlwidgets', and many other places where 'CSS' is valid.
Authors: John Coene [aut, cre]
Maintainer: John Coene <[email protected]>
License: MIT + file LICENSE
Version: 0.0.2
Built: 2026-05-15 09:39:30 UTC
Source: https://github.com/johncoene/linne

Help Index

Convenience Functions

Description

Convenience functions for common operations.

Usage

important_(value)

url_(value)

rgb_(r, g, b)

rgba_(r, g, b, a = 0.5)

Arguments

value

Value to use.
r, g, b, a

Red, green, blue, and alpha values.

Functions

  • important_() - Makes it such that the rule cannot be overwritten by other rules (other selections).

  • rgb_(), rgba_() - Functions for red, green, blue and alpha for transparency.

  • url_() - Wrap in a url CSS function call.

Examples

Linne$
 new()$
 rule(
   sel_id("id"),
   color = rgba_(255, 255, 255, .6),
   fontSize = important_(20)
 )

Linne

Description

Generate CSS from R code. Initialise a new CSS environment with new, use rule to define CSS rules.

Attributes

There are hundreds of attributes to pass to the three-dot construct (...), a comprehensive list of them can be found on w3schools.

Note that Linne accepts camelCase for convenience, e.g.: font-size or fontSize.

Methods

Public methods

Method define()

Usage
Linne$define(...)
Arguments
...

Named variables to define.

Details

Define variables.

Returns

Self: the Linne object.

Examples
Linne$new()$define(baseColor = "blue")

Method rule()

Usage
Linne$rule(selector, ...)
Arguments
selector

An object of class selector as returned by the ⁠sel_*⁠ family of functions.

...

Declarations: properties and their values. This accepts camelcase, e.g.: font-style or fontStyle.

Details

Rule

Define a CSS rule.

Returns

Self: the Linne object.

Examples
Linne$new()$rule(sel_id("myButton"), color = "blue", fontSize = 50)

Method build()

Usage
Linne$build()
Details

Builds CSS

Builds the CSS from definitions and rules.

Examples
Linne$
 new()$
 define(primary_color = 'red')$
 rule(
   sel_id("myButton"), 
   color = primary_color, 
   fontSize = 50
 )$
 rule(
   sel_class("container"),
   backgroundColor = primary_color
 )$
 build()

Method get_css()

Usage
Linne$get_css(build = TRUE)
Arguments
build

Whether to build the CSS with the build method.

Details

Retrieve the CSS

Returns

A string.

Examples
Linne$new()$rule(sel_id("myId"), fontSize = 20)$get_css()

Method show_css()

Usage
Linne$show_css(build = TRUE)
Arguments
build

Whether to build the CSS with the build method.

Details

Prints Generated CSS

Examples
Linne$new()$rule(sel_id("myButton"), color = "blue")$show_css()

Method import()

Usage
Linne$import(url)
Arguments
url

URL to import.

Details

Import

Import from a url or path.

Examples
Linne$new()$import('https://fonts.googleapis.com/css2?family=Roboto')

Method include()

Usage
Linne$include(build = TRUE)
Arguments
build

Whether to build the CSS with the build method.

Details

Include in Shiny

Includes the CSS in shiny, place the call to this method anywhere in the shiny UI.

Returns

htmltools::tags

Examples
# generate CSS
css <- Linne$
  new()$
  define(grey = '#c4c4c4')$
  rule(
    sel_id("myButton"), 
    backgroundColor = 'red', 
    fontSize = 20,
    color = grey
  )$
  rule(
    sel_class("aClass"),
    color = grey
  )

# include in an app
library(shiny)

ui <- fluidPage(
  css$include(),
  h1("Some text", class = "aClass"),
  actionButton("myButton", "Am I red?", class = "aClass")
)

server <- function(input, output){
  output$myPlot <- renderPlot(plot(cars))
}

if(interactive())
 shinyApp(ui, server)

Method write()

Usage
Linne$write(path = "style.css", pretty = FALSE, build = TRUE)
Arguments
path

Path to file.

pretty

Whether to keep tabs and newlines.

build

Whether to build the CSS with the build method.

Details

Save

Write the CSS to file.

Examples
if(interactive()) 
 Linne$new()$rule(sel_id("id"), fontStyle = "italic")$write("styles.css")

Method print()

Usage
Linne$print()
Details

Print

Prints information on the Linne object.

Method inject()

Usage
Linne$inject(build = TRUE, session = shiny::getDefaultReactiveDomain())
Arguments
build

Whether to build the CSS with the build method.

session

A valid shiny session.

Details

Inject CSS

Dynamically inject CSS from the server of a shiny application.

Examples
library(shiny)

ui <- fluidPage(
  useLinne(),
  actionButton("change", "Change me!")
)

server <- function(input, output){

  linne <- Linne$
    new()$
    rule(
      sel_id("change"),
      color = "white",
      backgroundColor = "black"
    )

  observeEvent(input$change, {
    linne$inject()
  })

}

if(interactive())
 shinyApp(ui, server)

Method clone()

The objects of this class are cloneable with this method.

Usage
Linne$clone(deep = FALSE)
Arguments
deep

Whether to make a deep clone.

Examples

## ------------------------------------------------
## Method `Linne$define`
## ------------------------------------------------

Linne$new()$define(baseColor = "blue")

## ------------------------------------------------
## Method `Linne$rule`
## ------------------------------------------------

Linne$new()$rule(sel_id("myButton"), color = "blue", fontSize = 50)

## ------------------------------------------------
## Method `Linne$build`
## ------------------------------------------------

Linne$
 new()$
 define(primary_color = 'red')$
 rule(
   sel_id("myButton"), 
   color = primary_color, 
   fontSize = 50
 )$
 rule(
   sel_class("container"),
   backgroundColor = primary_color
 )$
 build()

## ------------------------------------------------
## Method `Linne$get_css`
## ------------------------------------------------

Linne$new()$rule(sel_id("myId"), fontSize = 20)$get_css()

## ------------------------------------------------
## Method `Linne$show_css`
## ------------------------------------------------

Linne$new()$rule(sel_id("myButton"), color = "blue")$show_css()

## ------------------------------------------------
## Method `Linne$import`
## ------------------------------------------------

Linne$new()$import('https://fonts.googleapis.com/css2?family=Roboto')

## ------------------------------------------------
## Method `Linne$include`
## ------------------------------------------------

# generate CSS
css <- Linne$
  new()$
  define(grey = '#c4c4c4')$
  rule(
    sel_id("myButton"), 
    backgroundColor = 'red', 
    fontSize = 20,
    color = grey
  )$
  rule(
    sel_class("aClass"),
    color = grey
  )

# include in an app
library(shiny)

ui <- fluidPage(
  css$include(),
  h1("Some text", class = "aClass"),
  actionButton("myButton", "Am I red?", class = "aClass")
)

server <- function(input, output){
  output$myPlot <- renderPlot(plot(cars))
}

if(interactive())
 shinyApp(ui, server)


## ------------------------------------------------
## Method `Linne$write`
## ------------------------------------------------

if(interactive()) 
 Linne$new()$rule(sel_id("id"), fontStyle = "italic")$write("styles.css")

## ------------------------------------------------
## Method `Linne$inject`
## ------------------------------------------------

library(shiny)

ui <- fluidPage(
  useLinne(),
  actionButton("change", "Change me!")
)

server <- function(input, output){

  linne <- Linne$
    new()$
    rule(
      sel_id("change"),
      color = "white",
      backgroundColor = "black"
    )

  observeEvent(input$change, {
    linne$inject()
  })

}

if(interactive())
 shinyApp(ui, server)

Infixes

Description

Convenient pipes for more sophisticated selectors.

Usage

lhs %child% rhs

lhs %or% rhs

lhs %with% rhs

Arguments

lhs, rhs

Selectors as returned by ⁠sel_*⁠ family of functions.

Operators

  • %child% - Selects elements where right hand is child of left hand, e.g.: sel_tag('div') %child% sel_class('aClass') selects elements with aClass who are direct children of div tags.

  • %or% - Select left hand or right hand, e.g.: sel_id('myId') %or% sel_class('myClass') will select both the element with the id and elements with the class. Ideal to select and apply rules multiple elements at once.

  • %with% - Left hand selector with right hand selector, e.g.: sel_tag('div') %with% sel_class('aClass') selects a div with a class of aClass. Ideal to narrow down the selection.

Examples

# select all paragraph 'p' with "red" class
sel_tag("p") %with% sel_class("red")

# the other way around works equally well
sel_class("red") %with% sel_tag("p")

# select multiple elements
# where id = "x" or class = "center" 
sel_id("x") %or% sel_class("center")

# select element with id = "x" and parent's id = "y"
sel_id("y") %child% sel_id("y")

Selectors

Description

Create selectors to select particular elements.

Usage

sel_id(value, ns = NULL)

sel_input(value)

sel_all()

sel_class(value)

sel_tag(value)

sel_attr(attribute, value = NULL, tag = NULL)

Arguments

value

Value of selector.
ns

Shiny namespace, only applicable to sel_id.
attribute

Name of attribute.
tag

Name of tag.

Details

The functions will print in the console the CSS selector they compose.

Functions

  • sel_id() - Select an object by its id, e.g.: sel_id('btn') selects shiny::actionButton('btn', 'Button').

  • sel_all() - Selects everything.

  • sel_input() - Selects an input by its id, e.g.: sel_id('txt') selects shiny::textInput('txt', 'Text').

  • sel_class() - Select all elements bearing a specific class, e.g.: sel_class('cls'), selects shiny::h1('hello', class = 'cls').

  • sel_tag() - Select all tags, e.g.: sel_tag('p') selects p('hello').

  • sel_attr() - Select all tags with a specific attribute.

See Also

%with%, %or%, and %child% as well as when_active(), when_hover(), and when_focus() for more sophisticated element selection.

Examples

# select element where id = x
sel_id("x")

# select all elements with class = "container"
sel_class("container")

Dependency

Description

Imports dependencies necessary for the inject method to work. Pace this function in your shiny UI.

Usage

useLinne()

State

Description

Narrows selection to a specific state, e.g.: when it is hovered.

Usage

when_active(selector)

when_hover(selector)

when_focus(selector)

Arguments

selector

As returned by selectors.