Bootstrap download button

Delegates to shiny::downloadButton() and adapts its markup to Bootstrap 5.

Usage

bs_download_button(
  id,
  label = "Download",
  ...,
  icon = NULL,
  color = "primary",
  outline = FALSE,
  size = NULL,
  class = NULL
)

Arguments

id

Output id, matching the shiny::downloadHandler() assigned to output$id.

label

Button label (text or tags).

...

Additional content and named HTML attributes, forwarded to the anchor.

icon

Optional icon tag placed before the label. NULL (the default) renders no icon.

color

One of the eight Bootstrap theme colours, or "link".

outline

If TRUE, an outline button (.btn-outline-*).

size

"sm" or "lg".

class

Extra classes.

Value

An anchor tag styled as a Bootstrap button.

Details

shiny hardcodes class = "btn btn-default shiny-download-link". .btn-default is a Bootstrap 3 class with no Bootstrap 5 equivalent, so the button renders with the .btn box but no colour, border or hover state. We drop it and substitute a real 5.3 variant (.btn-primary, .btn-outline-secondary, ...), matching bs_button()'s API.

Everything else is left to shiny: the shiny-download-link class, the href / target / download attributes and the auto-enable dance (the anchor ships .disabled + aria-disabled and shiny's client enables it once the matching shiny::downloadHandler() is registered) are untouched, so output$id <- downloadHandler(...) works exactly as usual.

Unlike shiny, icon defaults to NULL: shiny's default is a Font Awesome icon, which is outside Bootstrap 5 and therefore outside this package.

See also

shiny::downloadHandler(), bs_download_link(), bs_button()

Examples

bs_download_button("report", "Download CSV")
#> <a id="report" href="" target="_blank" download aria-disabled="true" tabindex="-1" class="btn shiny-download-link disabled btn-primary">Download CSV</a>
bs_download_button("report", "Export", color = "secondary", outline = TRUE)
#> <a id="report" href="" target="_blank" download aria-disabled="true" tabindex="-1" class="btn shiny-download-link disabled btn-outline-secondary">Export</a>