How to display reactive UI for afvanced settings in modalDialog with Shinyusing moduals

Question

I'm designing an app that will have multiple tabs that all have basic ui features on the side, but hid various advanced UI options in a pop-up modal button. Some of these options are responsive to the dataset, for example choosing which rows to use.

I want to use modules to design the app, but am running into trouble getting reactive UI elements into the modals.

I think modalUI1 is getting the right namespace, but when I call uiOutput on the reactive ui element made by settingsServer1 it doesn't show up.

The closest slack post I found did something similar, but the modal they had static UI.Here

# Basic View Functions ----------------------------------------------------
# These modules setup the basic view for each analysis

simpleui <- function(id){
  ns <- NS(id)
  selectData <- selectInput(ns("d"), "Dataset:",
                    c("iris",
                      "mtcars",
                      "iris3"))
  outputRows <- verbatimTextOutput(ns("df"))
  settingsButton<-
    actionButton(
      ns("settings"),
      "Settings")
  tabPanel(id,
  tagList(
    p(),
    selectData,
    p(),
    outputRows,
    p(),
    settingsButton
  )
  )

}
view1 <- function(input, output, session) {
  reactiveDf <-  reactive({
    switch(input$d,
           "iris" = iris,
           "mtcars" = mtcars,
           "iris3"= iris3)
  })
  output$df <-  renderText({nrow(reactiveDf())})
  callModule(settingsServer1, "settings", reactiveDf)
  observeEvent(input$settings, {
    showModal(settngsModal(session$ns))
  })

  settngsModal <- function(ns) {
    # ns <- NS(id) ### This is inner UI so passed namespace from outer
    modalDialog(
      modalUI1("settings"), ### Call innerModalUI.
      # withTags({  # UI elements for the modal go in here
      #   fluidRow(
      #     column(4, "Inputs","Sectionnormal",uiOutput("nrowSlide")),
      #     column(4, "Inputs","Sectionnormal",uiOutput(ns("nrowSlide")))
      #   )}
      ,
      title = "Settings",
      footer = modalButton("Dismiss"),
      size = "l",
      easyClose = FALSE,
      fade = TRUE)
  }
}


# Advanced settings hidden in modal ---------------------------------------
# These functions should hide the advanced UI settings in a Modal.
modalUI1 <- function(ns) {
  ### Several UI elements 1 of which chooses which first N Rows.
  ### The slider is reactive
  # reactiveSlider <-  uiOutput("nrowSlide")
  withTags({  # UI elements for the modal go in here
    fluidRow(
      # print(ns("nrowSlide")),
      # print(input),
      column(4, "---------",uiOutput(("nrowSlide")), "---------")
    )
  })
}
settingsServer1 <- function(input, output, session, reactiveDf){
  output$nrowSlide <- renderUI({
    sliderInput("obs", "Number of observations:",
                min = 1, max = nrow(reactiveDf()), value = 1)
  })
}



# Basic Setup -------------------------------------------------------------
ui <- shinyUI(navbarPage("My Application",
                         simpleui("v1"),
                         simpleui("v2")
))


server <- function(input, output, session) {
  callModule(view1, "v1")
  callModule(view1, "v2")
  ### Also look for event to create a modal.
  ### This modal will have reactive items.



}

shinyApp(ui, server)