inst/template/R/leprechaun-utils.R

In leprechaun: Create Simple 'Shiny' Applications as Packages

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# DO NOT EDIT THIS FILE OR ADD ANYTHING TO IT #
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#' Create a Helper to Send Messages
#' 
#' Create a function to send custom messages to the front-end,
#' this function makes it such that the namespace is carried
#' along.
#' The namespace is appended as `ns`.
#' The namespace with the optional hyphen is 
#' included as `ns2`.
#' 
#' @param session Shiny session to derive namespace
#' @param prefix A prefix to add to all types.
#' Note that the prefix is followed by a hyphen `-`.
#' 
#' @examples 
#' \dontrun{
#' send_message <- make_send_message(session)
#' send_message("do-sth")
#' send_message("do-sth-else", x = 1)
#' 
#' # with prefix
#' send_message <- make_send_message(session, prefix = "PREFIX")
#' 
#' # this sends a mesasge of type:
#' # PREFIX-so-th
#' send_message("do-sth")
#' }
#' 
#' @noRd 
#' @keywords internal
make_send_message <- function(session, prefix = NULL){
  ns <- session$ns(NULL)

  ns2 <- ns
  if(length(ns) > 0 && ns != "")
    ns2 <- paste0(ns2, "-")

  function(msgId, ...){
    if(!is.null(prefix))
      msgId <- sprintf("%s-%s", prefix, msgId)
    
    session$sendCustomMessage(
      msgId,
      list(
        ns = ns,
        ns2 = ns2,
        ...
      )
    )
  }
}

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# DO NOT EDIT THIS FILE OR ADD ANYTHING TO IT #
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