docs: add note to documentation of teal_transform_module

R/module_teal_data.R

@@ -65,18 +65,6 @@ srv_teal_data <- function(id,
     data_out <- data_module(id = "data")
     data_handled <- reactive(tryCatch(data_out(), error = function(e) e))
     observeEvent(data_handled(), {
-      if (inherits(data_out, "reactive.event")) {
-        # This warning message partially detects when `eventReactive` is used in `data_module`.
-        warning(
-          paste(
-            "srv_teal_data",
-            "Using eventReactive in teal_transform module server code should be avoided as it",
-            "may lead to unexpected behavior. See the vignettes for more information ",
-            "(`vignette(\"data-transform-as-shiny-module\", package = \"teal\")`)."
-          )
-        )
-      }
-
       if (!inherits(data_handled(), "teal_data")) {
         is_transformer_failed[[id]] <- TRUE
       } else {

R/teal_data_module.R

@@ -104,6 +104,10 @@ teal_data_module <- function(ui, server, label = "data module", once = TRUE) {
 #' `shiny` module server function; that takes `id` and `data` argument,
 #' where the `id` is the module id and `data` is the reactive `teal_data` input.
 #' The server function must return reactive expression containing `teal_data` object.
+#'
+#' The server function definition should not use `eventReactive` as it may lead to
+#' unexpected behavior.
+#' See `vignettes("data-transform-as-shiny-module")` for more information.
 #' @param datanames (`character`)
 #'  Names of the datasets that are relevant for the module. The
 #'  filter panel will only display filters for specified `datanames`. The keyword `"all"` will show
@@ -149,6 +153,19 @@ teal_transform_module <- function(ui = function(id) NULL,
       ui = ui,
       server = function(id, data) {
         data_out <- server(id, data)
+
+        if (inherits(data_out, "reactive.event")) {
+          # This warning message partially detects when `eventReactive` is used in `data_module`.
+          warning(
+            paste(
+              "srv_teal_data",
+              "Using eventReactive in teal_transform module server code should be avoided as it",
+              "may lead to unexpected behavior. See the vignettes for more information ",
+              "(`vignette(\"data-transform-as-shiny-module\", package = \"teal\")`)."
+            )
+          )
+        }
+
         decorate_err_msg(
           assert_reactive(data_out),
           pre = sprintf("From: 'teal_transform_module()':\nA 'teal_transform_module' with \"%s\" label:", label),