R Shiny - 如何根据条件显示/隐藏“文件输入”（选项卡面板选择）

Question

I need to show "fileinput"/file upload option when a particular tabpanel is selected.

例如。有 3 个选项卡面板，如 A、B 和 C

When tab B is selected the "fileinput" option should appear and when A or C is selected, the "fileinput" option should be hidden from the sidebarpanel.

我尝试了以下但没有工作。任何人都可以帮忙吗？谢谢...

sidebarPanel(
conditionalPanel(condition = "input$id == 'B'", fileInput("file", "Choose xlsx file", accept = ".xlsx"))

 mainPanel(
          tabsetPanel(
            tabPanel("A", value = 'A', DT::dataTableOutput("Table A")),
            tabPanel("B", value = 'B', DT::dataTableOutput("Table B")),
            tabPanel("C", value = 'C', DT::dataTableOutput("Table C")),
            id ="tabselected"
          )
        )

Answer 1

您需要在带有. 的条件中使用tabsetPanel 的适当ID，而不是$。试试这个

library(readxl)

runApp(list(
  ui = shinyUI(
    fluidPage(
      
      sidebarLayout(
        sidebarPanel(
          conditionalPanel(condition = "input.tabselected == 'tab2'", 
                           fileInput("file", "Choose xlsx file", accept = ".xlsx")),
          selectInput(
            inputId = 'selected.indicator',
            label = 'Select an option: ',
            choices = colnames(mtcars)
          )
        ),
        mainPanel(
          tabsetPanel(
            tabPanel("A", value = 'tab1',  DTOutput("t1")),
            tabPanel("B", value = 'tab2',  DTOutput("t2")),
            tabPanel("C", value = 'tab3',  DTOutput("t3")),
            id ="tabselected"
          )
        )
      )
    )
  ),
  
  server = function(input, output, session) {
    output$t1 <- renderDT(cars)
    output$t3 <- renderDT(mtcars)
    
    mydata <- reactive({
      req(input$file)
      inFile <- input$file
      
      df <- read_excel(inFile$datapath)
    })
    
    output$t2 <- renderDT({
      req(mydata())
      mydata()
    })
    
  }
))