layout: support conditional UI (if statements) by allowing NULL in th…

…e UI
daattali · Aug 24, 2021 · 6396740 · 6396740
1 parent 806d344
commit 6396740
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Showing 3 changed files with 12 additions and 6 deletions.
diff --git a/R/dash_app.R b/R/dash_app.R
@@ -152,9 +152,11 @@ add_script <- function(app, script) {
 #' app <- dash_app()
 #'
 #' app %>% set_layout("hello", "Dash")
-#' app %>% set_layout(htmlDiv("hello"), "Dash")
-#' app %>% set_layout(list(htmlDiv("hello"), "Dash"))
-#' app %>% set_layout(htmlDiv(children = list(htmlDiv("hello"), "Dash")))
+#' app %>% set_layout(div("hello"), "Dash")
+#' app %>% set_layout(list(div("hello"), "Dash"))
+#' app %>% set_layout("Conditional UI using an if statement: ",
+#'                    if (TRUE) "rendered",
+#'                    if (FALSE) "not rendered")
 #' app %>% set_layout(function() { htmlDiv(children = list(htmlDiv("hello"), "Dash")) })
 #' @export
 set_layout <- function(app, ...) {

diff --git a/R/utils.R b/R/utils.R
@@ -14,6 +14,8 @@ componentify <- function(x) {
     dashHtmlComponents::htmlDiv(children = lapply(x, componentify))
   } else if (length(x) == 1) {
     dashHtmlComponents::htmlSpan(children = x)
+  } else if (is.null(x)) {
+    return(NULL)
   } else {
     stop("dash2: layout must be a dash component or list of dash components", call. = FALSE)
   }

diff --git a/man/set_layout.Rd b/man/set_layout.Rd