Login to single tabPanel in Shiny - r

Question

I have been trying to make a login for a single tabPanel in Shiny. I have used the shinyAlert method, (as described here: How to access Shiny tab ids for use with shinyalerts?) which works, but unfortunately, it shows parts of the tabPanel's content before the user is logged in.
Is there a way to change this? I am trying to figure out how to make the "backdrop" of the shinyAlert just a white page until the user is successfully logged in. I read that this might be possible with CSS, but it is unclear to me how.
Or is there another method to do this, that I haven't considered? I am pretty new to Shiny.
Edit: the relevant parts of the code.
ui <- fluidPage(navbarPage("Eksempel", theme = shinytheme("cerulean"),
tabPanel("Home", icon = icon("home"),
fluidRow(
box(
Title = "Welcome to the example layout",
width = 10,
solidHeader = TRUE,
"Welcome text")
)),
tabPanel("Prototype", icon = ("chart-line"),
fluidPage(tagList(
textInput("user", "User:"),
passwordInput("password", "Password:"),
uiOutput("secrets"))),
# other tabPanels
server <- function(input, output, session){
output$secrets <- renderUI({
req(input$user == "admin", input$password == "shiny")
fluidPage( #contents of tabPanel, containing different plots ect.
)
})
The contents of the fluidPage I am trying to hide works fine when I don't try to hide it.

Answer 1

You can use req in combination with a renderUI and uiOutput to hide stuff until someone authenticates.
library(shiny)
ui <- fluidPage(
tagList(
textInput("user", "User:"),
passwordInput("password", "Password:"),
uiOutput("secrets")
)
)
server <- function(input, output) {
output$secrets <- renderUI({
req(input$user == "admin", input$password == "stackoverflow")
wellPanel("Hello admin! These are the secrets!")
})
}
shinyApp(ui = ui, server = server)
If you want a more enterprise-ready approach, you can try ShinyProxy or Shiny-Server Pro.