R 闪亮的反应单选按钮

Question

在以下示例中，我有两个静态单选按钮，分别代表 mtcars 和 iris 数据集。做出选择后，会根据每个数据集中的数据向用户呈现第二组按钮。对于 mtcars 数据集，用户可以通过从唯一的化油器列表中选择进行过滤，或者在 iris 数据集的情况下选择物种。现在，我需要另一组基于 carb/species 按钮的按钮来进一步过滤数据。比如说，对于 mtcars 数据集，是与化油器选择相关的唯一齿轮选择列表，对于 Iris，是一组独特的花瓣长度。鉴于我正在尝试完成的实际应用，需要第三组反应式单选按钮是不可避免的。我只是不知道如何进行下一步。

ui.R

library(shinydashboard)

ui <- dashboardPage(
        dashboardHeader(title = "My DFS Dashboard"),
        dashboardSidebar(
                sidebarMenu(
                        menuItem("MTCARS", tabName = "dashboard", icon = icon("dashboard")),
                        menuItem("IRIS", tabName = "widgets", icon = icon("th"))
                )
        ),
        dashboardBody(
                fluidRow (
                        column(width = 3,
                               box(title = "Select Dataset", width = NULL, status = "primary", background = "aqua",
                                   radioButtons ("mydataset",
                                                 "",
                                                 inline = TRUE,
                                                 c("mtcars", "iris"),
                                                 selected = "mtcars"))),
                        column(width = 3, 
                               box(title="Select Filter One", width = NULL, status = "primary", background = "aqua",
                                   uiOutput("filter1"))),
                        column(width = 3, 
                               box(title = "Select Fitler Two", width = NULL, status = "primary", background = "aqua",
                                   uiOutput("filter2")))
                        )
                    )        
                )

server.R

library(tidyverse)


server <- function(input, output, session) {

data("mtcars")
data("iris")

cars <- mtcars
flowers <- iris

carbs <- cars %>%
        dplyr::select(carb)

carbs <- carbs$carb
carbs <- as.data.frame(carbs)
carbs <- unique(carbs$carb)

spec <- flowers %>%
                dplyr::select(Species)
spec <- unique(spec$Species)

               
        vards <- reactive ({
                switch(input$mydataset,
                       "mtcars" = carbs,
                       "iris" = spec,
                         )
        })
        output$filter1 <- renderUI({
                radioButtons("fil1","", choices=vards())
        })

}

Answer 1

也许这可能会有所帮助。您可以添加另一个 reactive 表达式来过滤您的数据集并获得第三组单选按钮的选择。我包含了isolate，以便第三组按钮不会对数据集的更改做出反应（仅第二个单选按钮的更改已经依赖于数据集）。请让我知道您是否考虑过这种行为。

server <- function(input, output, session) {
  
  data("mtcars")
  data("iris")
  
  cars <- mtcars
  flowers <- iris
  
  vards1 <- reactive({
    switch(input$mydataset,
           "mtcars" = unique(cars$carb),
           "iris" = unique(flowers$Species),
    )
  })
  
  vards2 <- reactive({
    req(input$fil1)
    if (isolate(input$mydataset) == "mtcars") {
      cars %>%
        filter(carb == input$fil1) %>%
        pull(gear) %>%
        unique()
    } else {
      flowers %>%
        filter(Species == input$fil1) %>%
        pull(Petal.Length) %>%
        unique()
    }
  })
  
  output$filter1 <- renderUI({
    radioButtons("fil1","", choices=vards1())
  })
  
  output$filter2 <- renderUI({
    radioButtons("fil2","", choices=vards2())
  })
  
}