R shiny - Unable to read input values when calling server via callModule

Question

Main app.R

header <- dashboardHeader(title = "R shiny Dashboard")


source("projects/customers/ui.R", local = TRUE)
customers_server <-
  source("projects/customers/server.R", local = TRUE)$value

sidebar <- dashboardSidebar(
  sidebarMenu(
    id = "sidebar",
    menuItem("Home", tabName = "home"),
    menuSubItem("Customers", tabName = "customers")
  )
)

body <- dashboardBody(tabItems(
  tabItem(tabName = "home",
          tags$div(
            HTML(
              '<h2 style="font-family:Arial; color:black;">Welcome</h2>'
            )
          )),
  tabItem(tabName = "customers",
          customers_ui("customers_ui"))
))

ui <- dashboardPage(header, sidebar, body)

server <- function(input, output, session) {
  observe({
    req(input$sidebar)  # Ensure 'sidebar' input is available before executing the rest of the code
    
    tab <- input$sidebar
    
    if (tab == "home") {
      # do nothing for home page
    }
    
    if (tab == "customers") {
      shinyjs::show("loading")
      callModule(customers_server, "customers_ui", session = session)
      shiny::removeModal()  # Remove the modal once the data is loaded
      shinyjs::hide("loading")
    }
  })
}

# Run the application
shinyApp(
  ui = ui,
  server = server,
  options = list(host = "0.0.0.0", port = 9999)
)

projects/customers/ui.R

source("projects/customers/modules.R")

customers_ui <- function(id) {
  ns <- NS(id)
  
  fluidPage(
    shinyjs::useShinyjs(),
    
    # Set the title of the page
    titlePanel(" Dashboard"),
    
    # Create tabs for Drift Metrics and Model Monitoring
    tabsetPanel(
      id = "tabs",
      tabPanel("Customer Stats", customerStatsUi(ns("customer_stats")))
    )
  )
}

Projects/customers/server.R

source("projects/customers/modules.R")

customers_server <- function(input, output, session) {
  ns <- session$ns
  
  timer <- reactiveTimer(2000)  # 2 second delay
  
  observeEvent(input$tabs, {
    shinyjs::show("loading")
    timer()  # Trigger the timer
  })
  
  customersStats(ns("customer_stats"))
  
  observeEvent(timer(), {
    shinyjs::hide("loading") 
  })
}

projects/customers/modules.R

customerStatsUi = function(id) {
  
  ns = NS(id)  # Create a namespaced ID function
  
  fluidPage(
    fluidRow(
      tags$head(tags$style(
        HTML(
          "
            .skin-blue .main-header .navbar {
              background-color: #1a8cff;
            }
            .skin-blue .main-header .logo {
              background-color: #1a8cff;
            }
            .box.box-primary {
              border-top-color: #1a8cff;
            }
            .sidebar-menu>li.active>a {
              border-left-color: #1a8cff;
            }
            .selectize-input {
              border-color: #1a8cff;
            }
          "
        )
      )),
      useShinyjs(),  # Enable shinyjs
      box(
        title = "Settings",
        width = 12,
        status = "primary",
        solidHeader = TRUE,
        column(
          4,
          dateInput(
            ns("date"),
            "Date:",
            value = Sys.Date()
          ),
          actionButton(ns("submit"), "Submit"),  # Add submit button
          textOutput(ns("selectedDate"))
        )
      )
    )
  )
}

customersStats = function(id) {
  moduleServer(id, function(input, output, session) {
    ns = session$ns  # Create a namespaced ID function
    print(input$date)
    output$selectedDate <- renderText({
      req(input$submit)
      paste("Selected date:", input$date)
    })
  })
}

The print(input$date) prints NULL. I'm unable to read any input$ values. If I call the server function directly instead of using callModule, everything works fine.

Could someone help me identify what I'm doing wrong here.

Tried experimenting with the code by print(ns("date")) which prints - [1] "customers_ui-customers_ui-customer_stats-date"

Does it mean I cannot access the date as input$date?`