css - Starting Shiny app after password input (with Shinydashboard)

In this topic is well explained how to start the shinyapp after some password input. I am trying to do the same, but instead of "navbarPage", I would like to have a "dashboardPage".

I tried to change the argument in do.call function form 'navbarPage' to 'dashboardPage', but the app crashes.

rm(list = ls())
library(shiny)

Logged = FALSE;
my_username <- "test"
my_password <- "test"

ui1 <- function(){
  tagList(
    div(id = "login",

        wellPanel(textInput("userName", "Username"),
                  passwordInput("passwd", "Password"),
                  br(),actionButton("Login", "Log in"))),
    tags$style(type="text/css", "#login {font-size:10px;   text-align: left;position:absolute;top: 40%;left: 50%;margin-top: -100px;margin-left: -150px;}")
  )}

ui2 <- function(){tagList(tabPanel("Test"))}

ui = (htmlOutput("page"))
server = (function(input, output,session) {


  USER <- reactiveValues(Logged = Logged)

  observe({ 
    if (USER$Logged == FALSE) {
      if (!is.null(input$Login)) {
        if (input$Login > 0) {
          Username <- isolate(input$userName)
          Password <- isolate(input$passwd)
          Id.username <- which(my_username == Username)

          Id.password <- which(my_password == Password)
          if (length(Id.username) > 0 & length(Id.password) > 0) {
            if (Id.username == Id.password) {
              USER$Logged <- TRUE
            } 
          }
        } 
      }
    }    
  })

  observe({
    if (USER$Logged == FALSE) {

      output$page <- renderUI({
        div(class="outer",do.call(bootstrapPage,c("",ui1())))
      })
    }
    if (USER$Logged == TRUE) 
    {
      output$page <- renderUI({

        div(class="outer",do.call(dashboardPage,c(inverse=TRUE,title = "Contratulations you got in!",ui2())))
      })
      print(ui)
    }
  })
})

runApp(list(ui = ui, server = server))

Answer

I woder if my code is enough to get you started on the "right" path. Please let me know if it is not the case.

The code below, if the login and password are correct, will display a shinydashboard.

but the following issues will need addressing:

• There is a problem in the css. I think you need to "reset" the css changed for the login operation to something more standard to shinydashboard (currently it is all white)


• If the password is wrong, the first observe will keep on "winning" on the renderUI (with or without a second observe, strictly speaking unnecessary hence eliminated) and the message relative to the wrong login is never executed.

There are number of things you could try to fix the above.

• For the css you could either re-set it, or elegantly have the login in a modal.


• For the second perhaps you could bring all the logic into the renderUI call. This would make sure that all cases are executed.

But please let me know if it is clear enough.

This is the code:

rm(list = ls())
library(shiny)
library(shinydashboard)

Logged = FALSE

my_username <- "test"
my_password <- "test"


ui1 <- function() {
  tagList(
    div(
      id = "login",
      wellPanel(
        textInput("userName", "Username"),
        passwordInput("passwd", "Password"),
        br(),
        actionButton("Login", "Log in")

      )
    ),
    tags$style(
      type = "text/css",
      "#login {font-size:10px;   text-align: left;position:absolute;top: 40%;left: 50%;margin-top: -100px;margin-left: -150px;}"
    )
  )
}

ui2 <- function() {

  tagList(dashboardHeader(),
          dashboardSidebar(),
          dashboardBody("Test"))
}


ui = (htmlOutput("page"))

server = function(input, output, session) {
  USER <- reactiveValues(Logged = Logged)


  observe({
    if (USER$Logged == FALSE) {
      if (!is.null(input$Login)) {
        if (length(input$Login) > 0) {
          Username <- isolate(input$userName)
          Password <- isolate(input$passwd)
          Id.username <- which(my_username == Username)
          Id.password <- which(my_password == Password)
          if (length(Id.username) > 0 &

              length(Id.password) > 0) {
            if (Id.username == Id.password) {
              USER$Logged <- TRUE
            }
          }
        }
      }
    }
  })


  output$page <- renderUI({
    if (USER$Logged == FALSE) {
      do.call(bootstrapPage, c("", ui1()))
    } else {
      do.call(dashboardPage, #c(inverse=TRUE,title = "Contratulations you got in!",
              ui2())
    }
  })
}


shinyApp(ui, server)

October 30, 2017 Update

It seems that the above code doesn't work anymore (thanks to @5249203 for pointing this out).

I've tried to fix it, but I haven't managed to make the do.call function work with dashboardBody (if somebody knows of a way, please let me know!).

Therefore I approached the problem in another way, thanks to recent shiny functions.

See what you think (of course as usual the solution is just a template needing extensions).

library(shiny)
library(shinydashboard)

Logged = FALSE
my_username <- "test"
my_password <- "test"


ui <- dashboardPage(skin='blue',
  dashboardHeader( title = "Dashboard"),
  dashboardSidebar(),
  dashboardBody("Test",
    # actionButton("show", "Login"),
  verbatimTextOutput("dataInfo")
    )
)

server = function(input, output,session) {


values <- reactiveValues(authenticated = FALSE)

# Return the UI for a modal dialog with data selection input. If 'failed' 
# is TRUE, then display a message that the previous value was invalid.
dataModal <- function(failed = FALSE) {
  modalDialog(
    textInput("username", "Username:"),
    passwordInput("password", "Password:"),
    footer = tagList(

      # modalButton("Cancel"),
      actionButton("ok", "OK")
    )
  )
}

# Show modal when button is clicked.  
# This `observe` is suspended only whith right user credential

obs1 <- observe({

  showModal(dataModal())
})

# When OK button is pressed, attempt to authenticate. If successful,
# remove the modal. 

obs2 <- observe({
  req(input$ok)
  isolate({
    Username <- input$username

    Password <- input$password
  })
  Id.username <- which(my_username == Username)
  Id.password <- which(my_password == Password)
  if (length(Id.username) > 0 & length(Id.password) > 0) {
    if (Id.username == Id.password) {
      Logged <<- TRUE
        values$authenticated <- TRUE
        obs1$suspend()
        removeModal()


    } else {
      values$authenticated <- FALSE
    }     
  }
  })


output$dataInfo <- renderPrint({
  if (values$authenticated) "OK!!!!!"

  else "You are NOT authenticated"
})

}

shinyApp(ui,server)