观察事件在第二和第三事件中的不同动作

Question

我尝试将actionButton与observeEvent结合使用。我的问题是:我可以用第二次点击按钮来定义不同的动作吗？就像这样

`observeEvent(input$verlauf,{
if (input$verlauf == 0){input$verlauf <- 1 & renderTable(BDI2())} 
else if (input$verlauf == 1){input$verlauf <- 2 & renderTable(BDI2())} 
else if (input$verlauf == 2){input$verlauf <- 3 & renderTable(BDI3())} 
else if (input$verlauf == 3){input$verlauf <- 4 & renderTable(BDI4())} 
else if (input$verlauf == 4){input$verlauf <- 5 & renderTable(BDI5())} 
else if (input$verlauf == 5){input$verlauf <- 6 & renderTable(BDI6())} 
else {}})`

在actionButton上的每一次单击都应该有一个不同的操作。如何在我的R/闪亮代码中做到这一点？它不起作用

(非常感谢:)

德鲁

Answer 1

您不能增加input$verlauf的值，但是可以创建一个reactiveValues对象并增加该值。下面是一个例子。

library(shiny)

shinyApp(
  ui = fluidPage(
    actionButton(inputId = "button",
                 label = "I am a Button. Click me!"),
    uiOutput("result")
  ),

  server = shinyServer(function(input, output, session){

    # MAKE A REACTIVE VALUES OBJECT HERE.  THIS BEHAVES LIKE A LIST, BUT 
    # CAN TRIGGER REACTIVE COMPONENTS
    Button <- reactiveValues(
      Click = 0
    )

    # Update the Button$Click object on each click of input$button
    observeEvent(input$button,
                 {
                   Button$Click <- input$button %% 8
                 })

    # Take an element of the vector.  This is changed every time
    # Button$Click changes.
    output$result <- 
      renderUI({
        p(c("It's raining tacos.",
            "From out of the sky.",
            "Tacos.",
            "No need to ask why.",
            "Just open your mouth",
            "and close your eyes...",
            "it's raining tacos.")[Button$Click])
      })
  })
)