用闪亮的方式在布局之间切换 [英] Switch between layouts reactively with shiny

问题描述

如何根据用户输入在 Shiny 中的页面布局之间切换?例如，我想在侧边栏布局和井面板布局之间切换，以使图形能够跨越整个页面.

How can I switch between page layouts in Shiny in response to user input? For example, I would like to switch between a sidebar layout to a wellpanel layout in order to have the graphics be able to span the entire page.

到目前为止，我所拥有的似乎即将开始工作，但我认为问题在于我无法重用从 renderUI 创建的界面.这是一个例子，

What I have so far seems to be on the verge of working, but I think the issue is that I can't reuse interfaces created from renderUI. Here is an example,

library(shiny)

shinyApp(
    shinyUI(
        fluidPage(
            radioButtons('layout', 'Layout:', choices=c('Sidebar', 'WellPanel'), inline=TRUE),
            conditionalPanel(
                condition = "input.layout == 'Sidebar'",
                uiOutput('sidebarUI')
            ),
            conditionalPanel(
                condition = "input.layout == 'WellPanel'",
                uiOutput('wellUI')
            )
        )
    ),
    shinyServer(function(input, output) {
        output$sidebarUI <- renderUI({
            sidebarLayout(
                sidebarPanel(
                    uiOutput('ui')
                ),
                mainPanel(
                    plotOutput('plot')
                )
            )
        })

        output$wellUI <- renderUI({
            fluidRow(
                column(12, plotOutput('plot')),
                column(12, wellPanel(uiOutput('ui')))
            )
        })

        output$ui <- renderUI({
            list(
                checkboxInput('inp1', 'Some stuff'),
                sliderInput('inp2', 'Some more stuff', 0, 10, 5)
            )
        })

        output$plot <- renderPlot({ plot(1) })
    })
)

如果其中一个条件面板被注释掉，那么另一个可以工作，但只有一个可以与两个条件面板一起使用.这是怎么做的?

If either one of the conditional panels is commented out, then the other one works, but only one will work with both conditional panels. How is this done?

推荐答案

您不能在 ui 中两次(或多次)调用输出，这就是为什么这不起作用，您可以在像这样的服务器:

Hi you can't call an output twice (or more) in the ui, that's why this isn't working, instead you can do all the work in the server like this :

library(shiny)

shinyApp(
  shinyUI(
    fluidPage(
      radioButtons('layout', 'Layout:', choices=c('Sidebar', 'WellPanel'), inline=TRUE),
      uiOutput('general_ui')
    )
  ),
  shinyServer(function(input, output) {
    output$general_ui <- renderUI({
      if (input$layout == "Sidebar") {
        sidebarLayout(
          sidebarPanel(
            uiOutput('ui')
          ),
          mainPanel(
            plotOutput('plot')
          )
        )
      } else if (input$layout == "WellPanel") {
        fluidRow(
          column(12, plotOutput('plot')),
          column(12, wellPanel(uiOutput('ui')))
        )
      }
    })

    output$ui <- renderUI({
      list(
        checkboxInput('inp1', 'Some stuff'),
        sliderInput('inp2', 'Some more stuff', 0, 10, 5)
      )
    })

    output$plot <- renderPlot({ plot(1) })
  })
)

但是有一个问题，当您在布局之间切换时，输入小部件会重新初始化...

But there's a catch, when you switch between layout, the input widgets are reinitialized...

但是你可以用这样的东西来修复它:

But you can fix it with something like this :

output$ui <- renderUI({
  list(
    checkboxInput('inp1', 'Some stuff'),
    if (is.null(input$inp2)) {
      sliderInput('inp2', 'Some more stuff', 0, 10, 5)
    } else {
      sliderInput('inp2', 'Some more stuff', 0, 10, input$inp2)
    }
  )
})

在创建您的小部件之前，您必须检查该值是否已经存在，您可以采用比上述更紧凑的方式:

Before creating your widget, you'll have to check if the value already exists, in a more compact way than above you can do that :

output$ui <- renderUI({
      list(
        checkboxInput(inputId = "inp1", label = 'Some stuff', value = input$inp1 %||% FALSE),
        sliderInput(inputId = "inp2", label = 'Some more stuff', min = 0, max = 10, value = input$inp2 %||% 5)
      )
    })

使用 %||% 函数定义如下:

With %||% function defined like this :

`%||%` <- function(a, b) {
  if (!is.null(a)) a else b
}

这篇关于用闪亮的方式在布局之间切换的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！