Rshiny - Disabling tabs / adding text to tabs - r

Question

I have a problem with shiny tabs. I want to create a navigation page with two tabs. Right to them, I would like to insert some user's login details. There is no option "text" or other to insert a text in the navbarPage. But I created an additionnal tab instead:
library(shiny)
runApp(list(
ui = navbarPage(
title="My App",
tabPanel("tab1 title"),
tabPanel("tab2 title"),
tabPanel("User: Madzia")),
server = function(input, output) { }
))
It is OK like this, but I do not want the third tab to be "selectible": I want it to be disabled, so that we cannot click on it - the same as on "My App" text. Do you have any idea about how to handle this problem?
Thank you! Best, Madzia

Answer 1

You can achieve disabling a tab with a tiny bit of javascript. I have an example of how to hide a tab (not disable) in recent blog post, you can see the code for that here. I modified that code a bit for disabling instead.
This code is hacky because it was done in 2 minutes but will work for a basic use case
library(shiny)
library(shinyjs)
jscode <- '
shinyjs.init = function() {
$(".nav").on("click", ".disabled", function (e) {
e.preventDefault();
return false;
});
}
'
css <- '
.disabled {
background: #eee !important;
cursor: default !important;
color: black !important;
}
'
shinyApp(
ui = fluidPage(
useShinyjs(),
extendShinyjs(text = jscode, functions = "init"),
tags$style(css),
checkboxInput("foo", "Disable tab2", FALSE),
tabsetPanel(
id = "navbar",
tabPanel(title = "tab1",
value = "tab1",
h1("Tab 1")
),
tabPanel(title = "tab2",
value = "tab2",
h1("Tab 2")
),
tabPanel(title = "tab3",
value = "tab3",
h1("Tab 3")
)
)
),
server = function(input, output) {
observe({
toggleClass(condition = input$foo,
class = "disabled",
selector = "#navbar li a[data-value=tab2]")
})
}
)
Edit I didn't fully read the question when I posted my answer, I just saw that you wanted a way to disable a tab and that was my answer. Your specific usecase (creating a tab only to show the name of a user) is a bit strange, but I suppose this will still work...

Answer 2

I would like to keep my previous answer in existence because it may be useful for someone in the future who wants to know how to disable a tab.
But for this specific problem, disabling the tab is not the correct approach. It makes more sense to simply add text to the tab (as Valter pointed out in a comment). If you look at the documentation for bootstrap, it says you can add text into the navbar by adding an html element with class navbar-text. I experimented with the HTML a little bit to figure out exactly where this needs to be done, and created a little function that will wrap around navbarPage() to allow you to add text to it.
Here's an example:
library(shiny)
navbarPageWithText <- function(..., text) {
navbar <- navbarPage(...)
textEl <- tags$p(class = "navbar-text", text)
navbar[[3]][[1]]$children[[1]] <- htmltools::tagAppendChild(
navbar[[3]][[1]]$children[[1]], textEl)
navbar
}
ui <- navbarPageWithText(
"Test app",
tabPanel("tab1", "tab 1"),
tabPanel("tab2", "tab 2"),
text = "User: Dean"
)
server <- function(input, output, session) {
}
shinyApp(ui = ui, server = server)