bslib (version 0.8.0)

bs_theme_dependencies: Compile Bootstrap Sass with (optional) theming

Description

bs_theme_dependencies() compiles Bootstrap Sass into CSS and returns it, along with other HTML dependencies, as a list of htmltools::htmlDependency()s. Most users won't need to call this function directly as Shiny & R Markdown will perform this compilation automatically when handed a bs_theme(). If you're here looking to create a themeable component, see bs_dependency().

Usage

bs_theme_dependencies(
  theme,
  sass_options = sass::sass_options_get(output_style = "compressed"),
  cache = sass::sass_cache_get(),
  jquery = jquerylib::jquery_core(3),
  precompiled = get_precompiled_option("bslib.precompiled", default = TRUE)
)

Value

Returns a list of HTML dependencies containing Bootstrap CSS, Bootstrap JavaScript, and jquery. This list may contain additional HTML dependencies if bundled with the theme.

Arguments

theme

A bs_theme() object.

sass_options

a sass::sass_options() object.

cache

This can be a directory to use for the cache, a FileCache object created by sass_file_cache(), or FALSE or NULL for no caching.

jquery

a jquerylib::jquery_core() object.

precompiled

Before compiling the theme object, first look for a precompiled CSS file for the theme_version(). If precompiled = TRUE and a precompiled CSS file exists for the theme object, it will be fetched immediately and not compiled. At the moment, we only provide precompiled CSS for "stock" builds of Bootstrap (i.e., no theming additions, Bootswatch themes, or non-default sass_options).

Sass caching and precompilation

If Shiny Developer Mode is enabled (by setting options(shiny.devmode = TRUE) or calling shiny::devmode(TRUE)), both sass caching and bslib precompilation are disabled by default; that is, a call to bs_theme_dependencies(theme) expands to bs_theme_dependencies(theme, cache = F, precompiled = F)). This is useful for local development as enabling caching/precompilation may produce incorrect results if local changes are made to bslib's source files.

See Also

Other Bootstrap theme functions: bs_add_variables(), bs_current_theme(), bs_dependency(), bs_global_theme(), bs_remove(), bs_theme(), bs_theme_preview()

Examples

if (FALSE) { # rlang::is_interactive()

# Function to preview the styling a (primary) Bootstrap button
library(htmltools)
button <- tags$a(class = "btn btn-primary", href = "#", role = "button", "Hello")
preview_button <- function(theme) {
  browsable(tags$body(bs_theme_dependencies(theme), button))
}

# Latest Bootstrap
preview_button(bs_theme())
# Bootstrap 3
preview_button(bs_theme(3))
# Bootswatch 4 minty theme
preview_button(bs_theme(4, bootswatch = "minty"))
# Bootswatch 4 sketchy theme
preview_button(bs_theme(4, bootswatch = "sketchy"))
}