闪亮：让renderUI对下拉列表做出反应not 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submitButton？

我有一个包含3件事情wellPanel：
1）我的下拉列表
2）一套动态输入（通过我的renderUI函数创建，取决于选择的＃1）
3 ）submitButton

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。当他们准备好所选输入的结果时，他们点击submitButton，并在mainPanel中获得结果。

问题：我的renderUI只对单击submitButton后的下拉选择作出反应。据我所知，我需要隔离一些东西或使用observeEvent，但我一直无法弄清楚。

简单的例子：

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

您需要引入两个变化。

1. 更改submitButton到actionButton（请参阅从@daattali评论）

2. 隔离renderText，并使其反应到actionButton。

查看下面的代码。

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))