Shiny：使 renderUI 对下拉列表做出反应，而不是 submitButton

Question

如何让 renderUI 对用户从下拉列表中选择不同的值做出反应，而无需单击我的提交按钮？

我有一个包含 3 个东西的 wellPanel：
1) 我的下拉列表
2) 一组动态输入（由我的 renderUI 函数创建，取决于 #1 中的选择）
3) 提交按钮

期望的行为：对下拉选择的更改为用户提供了不同的输入小部件以供使用。当他们准备好接收所选输入的结果时，他们单击提交按钮，然后在 mainPanel 中获得结果。

问题：我的 renderUI 仅在单击提交按钮后对下拉选择做出反应。据我所知，我需要隔离某些东西或使用observeEvent，但我无法弄清楚。

简化示例：

rm(list = ls())
library(shiny)

ui  <- fluidPage(
  fluidRow(
column(4,wellPanel(
  selectInput("analysis", label = "Type of Analysis:", 
              c("Award Total" = "total", 
                "Award Average" = "average"),
              width = validateCssUnit("70%")),
  uiOutput("filter_box"),
  submitButton()
    )),
column(8, textOutput("sample_text"))
  )
)

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

  output$filter_box <- renderUI({
if(input$analysis == "total"){
  tagList(radioButtons(inputId = "input1", label = "Select One:",c("A", "B", "C"), selected = "A"))
} else {
  tagList(checkboxGroupInput(inputId = "input2", label = "Select all that apply:",c("1","2","3","4","5")),
          dateRangeInput(inputId = "input3", label = "Enter Date Range"))
}
})

output$sample_text <- renderText({
  if(input$analysis == "total"){
    input$input1
  } else if(input$analysis == "average") {
    c(input$input2, input$input3)
  }
 })
}

runApp(list(ui = ui, server = server))

Answer 1

您需要引入两个更改。

1. 将submitButton 更改为actionButton（参见@daattali 的评论）

2. 隔离renderText，并使其响应actionButton。

参见下面的代码。

rm(list = ls())
library(shiny)

ui  <- fluidPage(
  fluidRow(
    column(4,wellPanel(
      selectInput("analysis", label = "Type of Analysis:", 
                  c("Award Total" = "total", 
                    "Award Average" = "average"),
                  width = validateCssUnit("70%")),
      uiOutput("filter_box"),
      actionButton(inputId = 'button_1',label = 'Apply Changes')
    )),
    column(8, textOutput("sample_text"))
  )
)

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

  output$filter_box <- renderUI({
    if(input$analysis == "total"){
      tagList(radioButtons(inputId = "input1", label = "Select One:",c("A", "B", "C"), selected = "A"))
    } else {
      tagList(checkboxGroupInput(inputId = "input2", label = "Select all that apply:",c("1","2","3","4","5")),
              dateRangeInput(inputId = "input3", label = "Enter Date Range"))
    }
  })

  output$sample_text <- renderText({
    input$button_1
    isolate({
      if(input$analysis == "total"){
        input$input1
      } else if(input$analysis == "average") {
        c(input$input2, input$input3)
      }
    })

  })
}

runApp(list(ui = ui, server = server))