Rshiny modal popup when good tab selected with navbarPage function - r

Question

I have a modular Rshiny application in which I want to display a dataset selection popup (modal) ONLY when the user is on the "TAB 1" tab.
Ideally, I would like this popup to be displayed only once on the first click on the right tab.
I really don't know how to get the input on which tab is active and then, create a counter to display popup only if counter == 1....
Here is my code :
1st module :
library(shiny)
library(shinyjs)
library(shinyWidgets)
#_________________________________________________________________
# MODULE 1 ----
#_________________________________________________________________
module1_ui <- function(id) {
ns <- NS(id)
tabPanel(
title = "Home",
shiny::tags$p(
"Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua."
)
)
}
module1_server <- function(id, r_global) {
moduleServer(id, function(input, output, session) {
})
}
2nd module :
#_________________________________________________________________
# MODULE 2 ----
#_________________________________________________________________
module2_ui <- function(id) {
ns <- NS(id)
tabPanel(
title = "Tab 1",
useShinyjs(),
actionLink(
inputId = ns("display_modal"),
label = "S\u00e9lectionner les donn\u00e9es",
style = "position: relative; left:90%"
),
tableOutput(outputId = ns("myTable"))
)
}
module2_server <- function(id, r_global) {
moduleServer(id, function(input, output, session) {
ns <- session$ns
#_________________________________________________________________
# MODAL DEFINITION ----
#_________________________________________________________________
dataModal <- function(failed = FALSE) {
modalDialog(
shiny::tags$h3("Choose dataset : "),
panel(
shinyWidgets::pickerInput(
inputId = ns("dataset_select"),
label = "Dataset :",
choices = c("dt1" = "dt1",
"dt2" = "dt2"),
multiple = FALSE,
options = list(`actions-box` = TRUE)
)
),
footer = tagList(
modalButton(label = "Cancel"),
actionButton(inputId = ns("ok"), label = "OK")
)
)
}
#_________________________________________________________________
# SHOW MODAL ----
#_________________________________________________________________
showModal(dataModal())
#_________________________________________________________________
# ACTION WHEN CLICKING ON OK MODAL ----
#_________________________________________________________________
observeEvent(input$ok, {
removeModal()
output$myTable = renderTable({
if(input$dataset_select == "dt1"){
iris
}else{
mtcars
}
})
})
#________________________________________________________________
# ACTION WHEN CLICKING ON LINK TO DISPLAY MODAL ----
#________________________________________________________________
observeEvent(input$display_modal, {
showModal(dataModal())
})
})
}
UI et SERVER:
#________________________________________________________________
# MAIN UI ----
#________________________________________________________________
app_ui <- function(request) {
tagList(
navbarPage(id = "main_menu", "My app",
module1_ui("mod1"),
module2_ui("mod2")
)
)
}
#________________________________________________________________
# MAIN SERVER ----
#________________________________________________________________
app_server <- function(input, output, session) {
r_global <- reactiveValues(data = NULL)
module1_server(id = "mod1", r_global = r_global)
module2_server(id = "mod2", r_global = r_global)
}
shinyApp(ui = app_ui, server = app_server)

Answer 1

One option would be to use a reactive in the main server to store the selected tab and pass it to the module 2 server via an additional argument. Inside the module 2 server you could use an observeEvent and check that you are on Tab 1. Additionally I implemented a counter as a reactiveVal such that the modal pops up only when listing Tab 1 the first time.
Code below includes only the module 2 server and the main server:
module2_server <- function(id, r_global, tab) {
moduleServer(id, function(input, output, session) {
ns <- session$ns
counter <- reactiveVal(1)
# _________________________________________________________________
# MODAL DEFINITION ----
# _________________________________________________________________
dataModal <- function(failed = FALSE) {
modalDialog(
shiny::tags$h3("Choose dataset : "),
panel(
shinyWidgets::pickerInput(
inputId = ns("dataset_select"),
label = "Dataset :",
choices = c(
"dt1" = "dt1",
"dt2" = "dt2"
),
multiple = FALSE,
options = list(`actions-box` = TRUE)
)
),
footer = tagList(
modalButton(label = "Cancel"),
actionButton(inputId = ns("ok"), label = "OK")
)
)
}
# _________________________________________________________________
# SHOW MODAL ----
# _________________________________________________________________
observeEvent(tab(), {
if (tab() == "Tab 1") {
if (counter() == 1) {
showModal(dataModal())
}
counter(counter() + 1)
}
})
# _________________________________________________________________
# ACTION WHEN CLICKING ON OK MODAL ----
# _________________________________________________________________
observeEvent(input$ok, {
removeModal()
output$myTable <- renderTable({
if (input$dataset_select == "dt1") {
iris
} else {
mtcars
}
})
})
# ________________________________________________________________
# ACTION WHEN CLICKING ON LINK TO DISPLAY MODAL ----
# ________________________________________________________________
observeEvent(input$display_modal, {
showModal(dataModal())
})
})
}
app_server <- function(input, output, session) {
r_global <- reactiveValues(data = NULL)
selected_tab <- reactive({
input$main_menu
})
module1_server(id = "mod1", r_global = r_global)
module2_server(id = "mod2", r_global = r_global, tab = selected_tab)
}