activate tabpanel from another tabpanel

Question

I want when i start the application the tab panel tab2 = desactivated, and will be activated once i click the button in the first tab panel tab1, i tried with shinyjs and th

Answer 1

Some small clarifications on the arguments value, id, and value working from @DeanAttali's reprex:

library("shiny")
library("shinyjs")
require("V8") ## req for shinyjs::extendShinyjs()

## JavaScript snipit that dis/enables the ABILITY to click the tab (without changing aesthetics)
app_jscode <-
  "shinyjs.disableTab = function(name) {
    var tab = $('.nav li a[data-value=' + name + ']');
    tab.bind('click.tab', function(e) {
      e.preventDefault();
      return false;
    });
    tab.addClass('disabled');
  }
  shinyjs.enableTab = function(name) {
    var tab = $('.nav li a[data-value=' + name + ']');
    tab.unbind('click.tab');
    tab.removeClass('disabled');
  }"
## css snipit that makes it LOOK like we are/n't able click the tab (with outchanging functionality)
app_css <-
  ".nav li a.disabled {
    background-color: #aaa !important;
    color: #333 !important;
    cursor: not-allowed !important;
    border-color: #aaa !important;
  }"

ui = fluidPage(
  shinyjs::useShinyjs(),
  shinyjs::extendShinyjs(text = app_jscode),
  shinyjs::inlineCSS(app_css),
  navbarPage(title = "Navbar title!", id = "navbarid",
             tabPanel(title = "tab1", ## id and value args not needed
                      br(),
                      p("in tab 1."),
                      actionButton("btn", label = "toggle locked tabs")),
             tabPanel(title = "tab2", ## id and value args not needed
                      p("in tab 2."))
  )
)
server = function(input, output, session) {
  ## Sisable tab2 on page load
  js$disableTab("tab2")
  
  observeEvent(input$btn, {
    ## Enable tab2 when clicking the button
    shinyjs::js$enableTab("tab2") ## On a tab's title
    ## Switch to tab2
    updateNavbarPage(session, "navbarid", "tab2") ## On navbar's id, tab's title
    #### Taking it further: 
    ## Also disable tab1 as a selection
    shinyjs::js$disableTab("tab1")
  })
}
shinyApp(ui = ui, server = server)

Answer 2

You need a bit of javascript to do this. Here's a solution using shinyjs. I also included some css to make it clear when the tab is disabled

jscode <- "
shinyjs.disableTab = function(name) {
  var tab = $('.nav li a[data-value=' + name + ']');
  tab.bind('click.tab', function(e) {
    e.preventDefault();
    return false;
  });
  tab.addClass('disabled');
}

shinyjs.enableTab = function(name) {
  var tab = $('.nav li a[data-value=' + name + ']');
  tab.unbind('click.tab');
  tab.removeClass('disabled');
}
"

css <- "
.nav li a.disabled {
  background-color: #aaa !important;
  color: #333 !important;
  cursor: not-allowed !important;
  border-color: #aaa !important;
}"

library(shiny)
library(shinyjs)
runApp(list(
  ui = fluidPage(
    useShinyjs(),
    extendShinyjs(text = jscode),
    inlineCSS(css),
    tabsetPanel(
      id = "navbar",
      tabPanel(title = "tab1", id = "tab1",
               br(),
               actionButton("btn", label = "View tab2 panel")),
      tabPanel(title = "tab2", id = "tab2")
    )
  ),
  server = function(input, output, session) {

    # disable tab2 on page load
    js$disableTab("tab2")

    observeEvent(input$btn, {
      # enable tab2 when clicking the button
      js$enableTab("tab2")
      # switch to tab2
      updateTabsetPanel(session, "navbar", "tab2")
    })
  }
))

You could also put the javascript in a separate file and use extendShinyjs(file = ...) instead of extendShinyjs(text = ...).