r - 从 SelectInput (R Shiny) 中的一组选项列表中获取组标签

Question

如何从 selectInput 中的选定输入中获取组名带有分组选项的下拉框？例如，我如何获得 Building在我选择 Bank 后内Building和 Nature在我选择 Bank 后内Nature ?

更新示例:

# demoing optgroup support in the `choices` arg
shinyApp(
  ui = fluidPage(
    selectInput("state", "Choose a word:",
      list(`Building` = list("Apartment", "Bank", "Hospital"),
           `Nature` = list("Bank", "River", "Orange"),
           `Color` = list("Blue", "Orange", "Red"))
    ),
    textOutput("result")
  ),
  server = function(input, output) {
    output$result <- renderText({
      paste("You chose", input$state)
    })
  }
)

一种方法是存储所有选项及其分组标签的变量并搜索该选项来自哪个组。但是当组之间存在重叠选择时，这不起作用。

Answer 1

您可以为每个输入指定一个值，而不是直接使用它们的名称，如下所示:

shinyApp(
  ui = fluidPage(
    selectInput("state", "Choose a word:",
                list(`Building` = list("Apartment"="ap", "Bank"="bk", "Hospital"="hp"),
                     `Nature` = list("Bank"="bk1", "River"="rv", "Orange"="or"),
                     `Color` = list("Blue"="bl", "Orange"="or1", "Red"="rd"))
    ),
    textOutput("result")
  ),
  server = function(input, output) {
    output$result <- renderText({
      paste("You chose", input$state)
    })
  }
)