How to render an input widget in a collapsed menu item?

Question

I am trying to render a checkbox menu in a collapsed menu item in shinydashboard, but I cannot get it to work. So far, I have only found an similar github issue when rendering to the dashboardBody, but I couldn't figure out how that would apply to the siderbarMenu.

library('shiny')
library("shinydashboard")

header <- dashboardHeader()

sidebar <- dashboardSidebar(
  sidebarMenu(
    menuItem("Inputs", icon = icon("bar-chart-o"), tabName = "tabOne",
             uiOutput('mymenu')
    )
  )
)

body <- dashboardBody(
  h3('nothing here')
)

shinyApp(
  ui = dashboardPage(header, sidebar, body),
  server = function(input, output) {


    output$mymenu <- renderUI({

      checkboxGroupInput('mymenu', 'lettersMenu',
                         letters[1:5],
                         letters[1:5])
    })
  }
)

Answer 1

I think the problem is that there is nothing triggering this renderUI. Try adding this to your code:

outputOptions(output, "mymenu", suspendWhenHidden = FALSE)

edit

library('shiny')
library("shinydashboard")

header <- dashboardHeader()

sidebar <- dashboardSidebar(
  sidebarMenu(
    menuItem("Inputs", icon = icon("bar-chart-o"), tabName = "tabOne",
             uiOutput('mymenu')
    )
  )
)

body <- dashboardBody(
  h3('nothing here')
)

shinyApp(
  ui = dashboardPage(header, sidebar, body),
  server = function(input, output) {


    output$mymenu <- renderUI({

      checkboxGroupInput('mymenu', 'lettersMenu',
                         letters[1:5],
                         letters[1:5])
    })
    outputOptions(output, "mymenu", suspendWhenHidden = FALSE)
  }
)