条件输入列表闪亮r

Question

Imagine I've the following example, where I select one of three numbers, and than I have a selectlist with the number I choose plus 1, 2 and 3 if it is 1, or I have the number plus 10, 11 or 12, otherwise.

I'm having troubles when I try to use the input.sel as a variable, can someone explain why it is ok in the condition but it is not ok to use it as a variable?

conditionalPanel("input.sidebarmenu === 'dashboard8'",
                        selectInput("sel", "Select:", c(1,2,3), selected = "1"),

    conditionalPanel(
         condition = "input.sel == '1'",
         selectInput("Role1", "Role:", c(input.sel+10,input.sel+11,input.sel+12 ), selected = "All")),
    conditionalPanel(
         condition = "input.sel != '1'",
         selectInput("Role2", "Role:", c(input.sel+1,input.sel+2,input.sel+3) , selected = "All")                            
),

Answer 1

You can use something like :

In UI

selectInput("Role1", "Role:", "", selected = ""))

and in Server

observe({
updateSelectInput(session,"Role1",choices=input$sel+10:12,selected= input$sel+10:12))
})

or better observeEvent(input$sel,...) to change input only when sel changed