R/backlink_Input.R

In shinyGovstyle: Custom Gov Style Inputs for Shiny

#' Back Link Function
#'
#' This function adds a back link to the page
#' @param inputId The input slot that will be used to access the value
#' @param label The link text for the backlink, default is "Back"
#' @return a backlink HTML shiny tag object
#' @family Govstyle navigation
#' @export
#' @examples
#' ui <- shiny::fluidPage(
#'   header(
#'     org_name = "Example",
#'     service_name = "User Examples",
#'     logo = "shinyGovstyle/images/moj_logo.png"
#'   ),
#'   shiny::navlistPanel(
#'     "",
#'     id = "nav",
#'     widths = c(2, 10),
#'     well = FALSE,
#'     # Create first panel
#'     shiny::tabPanel(
#'       "Select Types",
#'       value = "panel1",
#'       gov_layout(
#'         size = "two-thirds",
#'         backlink_Input("link1"),
#'         shiny::tags$br(),
#'         shiny::tags$br()
#'       )
#'     ),
#'     shiny::tabPanel(
#'       "Tab2",
#'       value = "panel2"
#'     )
#'   ),
#'   shinyGovstyle::footer(full = TRUE)
#' )
#'
#' server <- function(input, output, session) {
#'   # Slightly confused in that it goes forward rather than back
#'   # but shows how to use
#'   observeEvent(input$link1, {
#'     updateTabsetPanel(session, "nav", selected = "panel2")
#'   })
#' }
#'
#' if (interactive()) shinyApp(ui = ui, server = server)
backlink_Input <- # nolint
  function(
    inputId, # nolint
    label = "Back"
  ) {
    value <- shiny::restoreInput(id = inputId, default = NULL)
    gov_back_link <- shiny::actionLink(
      label = label,
      inputId = inputId,
      class = paste0("govuk-back-link"),
      `data-val` = value
    )
    attachDependency(gov_back_link)
  }