shiny modules + reactlog + not independent

shiny_modules_reactlog_not_independent

options(shiny.reactlog = TRUE)
library(shiny)
library(reactlog)

mod_iris_ui <- function(id) {
  ns <- NS(id)

  tagList(
    fluidRow(
      column(
        2,
        selectInput(
          inputId = ns("species"),
          label = "species",
          choices = list(
            "loading..." = 1
          ),
          selected = 1
        )
      ),
      column(
        10,
        plotOutput(ns("speciesplot"))
      )
    )
  )
}

mod_iris <- function(input, output, session) {
  ns <- session$ns

  df <- reactive({
    req(ns(input$open_tab) == "iris")

    df <- iris
  })

  observe({
    req(ns(input$open_tab) == "iris")

    values <- as.character(unique(df()[["Species"]]))

    updateSelectInput(session, "species",
      choices = values,
      selected = values[1]
    )
  })

  output$speciesplot <- renderPlot({
    hist(iris[iris$Species == input$species, 1])
  })
}

mod_mtcars_ui <- function(id) {
  ns <- NS(id)

  tagList(
    fluidRow(
      column(
        2,
        selectInput(
          inputId = ns("gear"),
          label = "gear",
          choices = list(
            "loading..." = 1
          ),
          selected = 1
        )
      ),
      column(
        10,
        plotOutput(ns("gearplot"))
      )
    )
  )
}

mod_mtcars <- function(input, output, session) {
  ns <- session$ns

  df <- reactive({
    req(ns(input$open_tab) == "mtcars")

    df <- mtcars
  })

  observe({
    req(ns(input$open_tab) == "mtcars")

    values <- unique(df()[["gear"]])

    updateSelectInput(session, "gear",
      choices = values,
      selected = values[1]
    )
  })

  output$gearplot <- renderPlot({
    hist(mtcars[mtcars$gear == input$gear, 1])
  })
}

ui <- tagList(
  navbarPage(
    title = "App",
    id = "open_tab",

    tabPanel(
      "iris",
      mod_iris_ui("iris")
    ),

    tabPanel(
      "mtcars",
      mod_mtcars_ui("mtcars")
    )
  )
)

server <- function(input, output, session) {
  callModule(
    mod_iris,
    "iris"
  )

  callModule(
    mod_mtcars,
    "mtcars"
  )
}

shinyApp(ui = ui, server = server)

The first answer is definitely a way to go for more complicated situations.
However, for your example I checked and if you remove all the req() the panels operate independently.

this example wasn't great in illustrating the non-independence and i'm still not 100% clear in my actual case what was causing the tabs to be non-independent. but using req() and the open_tab helped significantly and ensured that all of the modules run only when their tabs are open. thank you both very much!!!