R/css_class.R

In daqana/dqshiny: Enhance Shiny Apps with Customizable Modules

#' Change the state of a shiny interface element
#'
#' @description Those functions can be used to change an elements classes.
#'
#' @note If you have trouble with these functions, please make sure that you
#' either - use any dqshiny element in your UI - load the package with
#' \code{\link{library}} - use \code{\link{init}} at the beginning of your UI!
#'
#' @param ids Character vector, id(s) of the element(s) to change.
#' @param class_name Name of the class to add/remove/toggle.
#'
#' @export
#' @family js handler
#' @author richard.kunze
#' @examples ## Only run examples in interactive R sessions
#' if (interactive()) {
#'
#' library(shiny)
#' shinyApp(
#'   ui = fluidPage(
#'     tags$head(tags$style(".orange{background:#ff8f00}")),
#'     actionButton("add", "Add Class"),
#'     actionButton("remove", "Remove Class"),
#'     actionButton("toggle", "Toggle Class"),
#'     actionButton("toggle_cond", "Toggle Class with Condition"),
#'     checkboxInput("condition", "orange"),
#'     fluidRow(id = "row",
#'       dq_space(), # this is needed to make everything work
#'       actionButton("example", "EXAMPLE"),
#'       dq_space() # this is just for the alignment ;)
#'    )
#'   ),
#'   server = function(input, output) {
#'     observeEvent(input$add, add_class("row", "orange"))
#'     observeEvent(input$remove, remove_class("row", "orange"))
#'     observeEvent(input$toggle, toggle_class("row", "orange"))
#'     observeEvent(
#'       input$toggle_cond,
#'       toggle_class("row", "orange", input$condition)
#'     )
#'   }
#' )
#'
#' }
add_class <- function(ids, class_name) {
  send_message(
    type = "dqToggleClass",
    ids = unname(ids),
    className = class_name,
    state = TRUE
  )
}

#' @export
#' @rdname add_class
remove_class <- function(ids, class_name) {
  send_message(
    type = "dqToggleClass",
    ids = unname(ids),
    className = class_name,
    state = FALSE
  )
}

#' @param condition Condition to use for toggling the class, can be of length
#' one or length of ids.
#' @export
#' @rdname add_class
toggle_class <- function(ids, class_name, condition = NULL) {
  if (length(condition) > 0L) condition <- rep_len(condition, length(ids))
  lapply(seq_along(ids), function(i) {
    send_message(
      type = "dqToggleClass",
      ids = unname(ids[i]),
      className = class_name,
      state = condition[i]
    )
  })
}