introduce decorators for tm_g_barchart_simple (#1267)

Part of insightsengineering/teal#1371

#### Checklist for final review:

- Has documentation:
- [ ] `` #' @param decorators `r roxygen_decorators_param("tm_X_XXX")`
``
    - [ ] Section for decorators
- [ ] In case of multiple decorators, section has pseudo code explaining
how to limit calls
- [ ] Code shows in "Show R code"
- [ ] Reporter shows both the outputs and code
- [ ] Fix order of `assert_decorators` function (`null.ok = TRUE` is
sometimes second argument and looks better at 3^rd)

#### Example

<details><summary> Working Example </summary>

```r
devtools::load_all("../teal.reporter")
devtools::load_all("../teal")
devtools::load_all(".")

library(nestcolor)
library(dplyr)

data <- teal_data()
data <- within(data, {
  ADSL <- tmc_ex_adsl %>%
    mutate(ITTFL = factor("Y") %>%
             with_label("Intent-To-Treat Population Flag"))
  ADAE <- tmc_ex_adae %>%
    filter(!((AETOXGR == 1) & (AESEV == "MILD") & (ARM == "A: Drug X")))
})
join_keys(data) <- default_cdisc_join_keys[names(data)]

ADSL <- data[["ADSL"]]
ADAE <- data[["ADAE"]]

caption_decorator <- function(default_caption = "I am a good decorator", .var_to_replace = "plot") {
  teal_transform_module(
    label = "Caption",
    ui = function(id) shiny::textInput(shiny::NS(id, "footnote"), "Footnote", value = default_caption),
    server = make_teal_transform_server(
      substitute({
        .var_to_replace <- .var_to_replace + ggplot2::labs(caption = footnote)
      }, env = list(.var_to_replace = as.name(.var_to_replace)))
    )
  )
}

head_decorator <- function(default_value = 6, .var_to_replace = "object") {
  teal_transform_module(
    label = "Head",
    ui = function(id) shiny::numericInput(shiny::NS(id, "n"), "N rows", value = default_value),
    server = make_teal_transform_server(
      substitute({
        .var_to_replace <- utils::head(.var_to_replace, n = n)
      }, env = list(.var_to_replace = as.name(.var_to_replace)))
    )
  )
}

app <- init(
  data = data,
  modules = modules(
    tm_g_barchart_simple(
      label = "ADAE Analysis",
      x = data_extract_spec(
        dataname = "ADSL",
        select = select_spec(
          choices = variable_choices(
            ADSL,
            c(
              "ARM", "ACTARM", "SEX",
              "RACE", "ITTFL", "SAFFL", "STRATA2"
            )
          ),
          selected = "ACTARM",
          multiple = FALSE
        )
      ),
      fill = list(
        data_extract_spec(
          dataname = "ADSL",
          select = select_spec(
            choices = variable_choices(
              ADSL,
              c(
                "ARM", "ACTARM", "SEX",
                "RACE", "ITTFL", "SAFFL", "STRATA2"
              )
            ),
            selected = "SEX",
            multiple = FALSE
          )
        ),
        data_extract_spec(
          dataname = "ADAE",
          select = select_spec(
            choices = variable_choices(ADAE, c("AETOXGR", "AESEV", "AESER")),
            selected = NULL,
            multiple = FALSE
          )
        )
      ),
      x_facet = list(
        data_extract_spec(
          dataname = "ADAE",
          select = select_spec(
            choices = variable_choices(ADAE, c("AETOXGR", "AESEV", "AESER")),
            selected = "AETOXGR",
            multiple = FALSE
          )
        ),
        data_extract_spec(
          dataname = "ADSL",
          select = select_spec(
            choices = variable_choices(
              ADSL,
              c(
                "ARM", "ACTARM", "SEX",
                "RACE", "ITTFL", "SAFFL", "STRATA2"
              )
            ),
            selected = NULL,
            multiple = FALSE
          )
        )
      ),
      y_facet = list(
        data_extract_spec(
          dataname = "ADAE",
          select = select_spec(
            choices = variable_choices(ADAE, c("AETOXGR", "AESEV", "AESER")),
            selected = "AESEV",
            multiple = FALSE
          )
        ),
        data_extract_spec(
          dataname = "ADSL",
          select = select_spec(
            choices = variable_choices(
              ADSL,
              c(
                "ARM", "ACTARM", "SEX",
                "RACE", "ITTFL", "SAFFL", "STRATA2"
              )
            ),
            selected = NULL,
            multiple = FALSE
          )
        )
      ),
      decorators = list(plot = caption_decorator('Marcin', 'plot'))
    )
  )
)
if (interactive()) {
  shinyApp(app$ui, app$server)
}


```

</details>

---------

Signed-off-by: André Veríssimo <[email protected]>
Co-authored-by: Lluís Revilla <[email protected]>
Co-authored-by: André Veríssimo <[email protected]>
Co-authored-by: Lluís Revilla <[email protected]>

Author: 3 people

R/tm_g_barchart_simple.R

@@ -12,9 +12,18 @@
 #' @param x_facet (`data_extract_spec`)\cr row-wise faceting groups.
 #' @param y_facet (`data_extract_spec`)\cr column-wise faceting groups.
 #' @param plot_options (`list`)\cr list of plot options.
+#' @param decorators `r roxygen_decorators_param("tm_g_barchart_simple")`
 #'
 #' @inherit module_arguments return seealso
 #'
+#' @section Decorating `tm_g_barchart_simple`:
+#'
+#' This module generates the following objects, which can be modified in place using decorators:
+#' - `plot` (`ggplot2`)
+#'
+#' For additional details and examples of decorators, refer to the vignette
+#' `vignette("decorate-modules-output", package = "teal")` or the [`teal_transform_module()`] documentation.
+#'
 #' @examplesShinylive
 #' library(teal.modules.clinical)
 #' interactive <- function() TRUE
@@ -146,7 +155,8 @@ tm_g_barchart_simple <- function(x = NULL,
                                  plot_width = NULL,
                                  pre_output = NULL,
                                  post_output = NULL,
-                                 ggplot2_args = teal.widgets::ggplot2_args()) {
+                                 ggplot2_args = teal.widgets::ggplot2_args(),
+                                 decorators = NULL) {
   message("Initializing tm_g_barchart_simple")
   checkmate::assert_string(label)
   checkmate::assert_list(plot_options, null.ok = TRUE)
@@ -171,6 +181,8 @@ tm_g_barchart_simple <- function(x = NULL,
   checkmate::assert_class(pre_output, classes = "shiny.tag", null.ok = TRUE)
   checkmate::assert_class(post_output, classes = "shiny.tag", null.ok = TRUE)
   checkmate::assert_class(ggplot2_args, "ggplot2_args")
+  decorators <- normalize_decorators(decorators)
+  assert_decorators(decorators, names = "plot", null.ok = TRUE)
 
   plot_options <- utils::modifyList(
     list(stacked = FALSE), # default
@@ -190,7 +202,8 @@ tm_g_barchart_simple <- function(x = NULL,
       y_facet = y_facet,
       plot_height = plot_height,
       plot_width = plot_width,
-      ggplot2_args = ggplot2_args
+      ggplot2_args = ggplot2_args,
+      decorators = decorators
     ),
     datanames = "all"
   )
@@ -249,6 +262,7 @@ ui_g_barchart_simple <- function(id, ...) {
             is_single_dataset = is_single_dataset_value
           )
         },
+        ui_decorate_teal_data(ns("decorator"), decorators = select_decorators(args$decorators, "plot")),
         teal.widgets::panel_group(
           teal.widgets::panel_item(
             "Additional plot settings",
@@ -336,7 +350,8 @@ srv_g_barchart_simple <- function(id,
                                   y_facet,
                                   plot_height,
                                   plot_width,
-                                  ggplot2_args) {
+                                  ggplot2_args,
+                                  decorators) {
   with_reporter <- !missing(reporter) && inherits(reporter, "Reporter")
   with_filter <- !missing(filter_panel_api) && inherits(filter_panel_api, "FilterPanelAPI")
   checkmate::assert_class(data, "reactive")
@@ -506,13 +521,16 @@ srv_g_barchart_simple <- function(id,
           )
         )) %>%
         teal.code::eval_code(code = plot_call)
-
-      # explicitly calling print on the plot inside the qenv evaluates
-      # the ggplot call and therefore catches errors
-      teal.code::eval_code(all_q, code = quote(print(plot)))
     })
 
-    plot_r <- reactive(all_q()[["plot"]])
+    decorated_all_q_code <- srv_decorate_teal_data(
+      "decorator",
+      data = all_q,
+      decorators = select_decorators(decorators, "plot"),
+      expr = print(plot)
+    )
+
+    plot_r <- reactive(decorated_all_q_code()[["plot"]])
 
     output$table <- renderTable({
       req(iv_r()$is_valid())
@@ -550,7 +568,7 @@ srv_g_barchart_simple <- function(id,
 
     teal.widgets::verbatim_popup_srv(
       id = "rcode",
-      verbatim_content = reactive(teal.code::get_code(all_q())),
+      verbatim_content = reactive(teal.code::get_code(req(decorated_all_q_code()))),
       title = "Bar Chart"
     )
 
@@ -569,7 +587,7 @@ srv_g_barchart_simple <- function(id,
           card$append_text("Comment", "header3")
           card$append_text(comment)
         }
-        card$append_src(teal.code::get_code(all_q()))
+        card$append_src(teal.code::get_code(req(decorated_all_q_code())))
         card
       }
       teal.reporter::simple_reporter_srv("simple_reporter", reporter = reporter, card_fun = card_fun)