Add inline CSS to a Shiny app. This is simply a convenience function that gets called from a Shiny app's UI to make it less tedious to add inline CSS. If there are many CSS rules, it is recommended to use an external stylesheet.

CSS is a simple way to describe how elements on a web page should be displayed (position, colour, size, etc.). You can learn the basics at W3Schools.

inlineCSS(rules)

Arguments

rules

The CSS rules to add. Can either be a string with valid CSS code, or a named list of the form list(selector = declarations), where selector is a valid CSS selector and declarations is a string or vector of declarations. See examples for clarification.

Value

Inline CSS code that is automatically inserted to the app's <head> tag.

Examples

if (interactive()) {
  library(shiny)

  # Method 1 - passing a string of valid CSS
  shinyApp(
    ui = fluidPage(
      inlineCSS("#big { font-size:30px; }
                 .red { color: red; border: 1px solid black;}"),
      p(id = "big", "This will be big"),
      p(class = "red", "This will be red and bordered")
    ),
    server = function(input, output) {}
  )

  # Method 2 - passing a list of CSS selectors/declarations
  # where each declaration is a full declaration block
  shinyApp(
    ui = fluidPage(
      inlineCSS(list(
        "#big" = "font-size:30px",
        ".red" = "color: red; border: 1px solid black;"
      )),
      p(id = "big", "This will be big"),
      p(class = "red", "This will be red and bordered")
    ),
    server = function(input, output) {}
  )

  # Method 3 - passing a list of CSS selectors/declarations
  # where each declaration is a vector of declarations
  shinyApp(
    ui = fluidPage(
      inlineCSS(list(
        "#big" = "font-size:30px",
        ".red" = c("color: red", "border: 1px solid black")
      )),
      p(id = "big", "This will be big"),
      p(class = "red", "This will be red and bordered")
    ),
    server = function(input, output) {}
  )
}