Convert validate example to single-file app. Closes #1345 (#1347)

R/utils.R

@@ -1092,15 +1092,16 @@ reactiveStop <- function(message = "", class = NULL) {
 #'   \code{shiny-output-error-} prepended to this value.
 #' @export
 #' @examples
-#' # in ui.R
-#' fluidPage(
+#' ## Only run examples in interactive R sessions
+#' if (interactive()) {
+#'
+#' ui <- fluidPage(
 #'   checkboxGroupInput('in1', 'Check some letters', choices = head(LETTERS)),
 #'   selectizeInput('in2', 'Select a state', choices = state.name),
 #'   plotOutput('plot')
 #' )
 #'
-#' # in server.R
-#' function(input, output) {
+#' server <- function(input, output) {
 #'   output$plot <- renderPlot({
 #'     validate(
 #'       need(input$in1, 'Check at least one letter!'),
@@ -1109,6 +1110,10 @@ reactiveStop <- function(message = "", class = NULL) {
 #'     plot(1:10, main = paste(c(input$in1, input$in2), collapse = ', '))
 #'   })
 #' }
+#'
+#' shinyApp(ui, server)
+#'
+#' }
 validate <- function(..., errorClass = character(0)) {
   results <- sapply(list(...), function(x) {
     # Detect NULL or NA