本文介绍了R SHINY-ui输出不在menuItem内渲染的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!

问题描述

问题

为什么在server上生成并使用uiOutput()呈现的sliderInput()不在menuItem()中显示?

示例

在这个简单的应用程序中,我在server上生成了一个sliderInput(请注意,menuItem被故意注释掉了),它按照预期工作

library(shiny)
library(shinydashboard)

rm(ui, server)

ui <- dashboardPage(
    dashboardHeader(),

    dashboardSidebar(
        sidebarMenu(
            #menuItem(text = "data options",
                      checkboxGroupInput(inputId = "cbg_group1", label = "group 1",
                                         choices = c("some","check","boxes","to","choose","from") ),
                       uiOutput("sli_val1"),
                       checkboxGroupInput(inputId = "cbg_group2", label = "group 2",
                                          choices = c("another","set","of","check","boxes") ),
            #                ),
            menuItem(text = "another tab")
            )
    ),
    dashboardBody()
)

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

    withProgress(message = "loading page", value=0.1, {
        ## simulate loading some data
        Sys.sleep(3)

        ## slider input
        output$sli_val1 <- renderUI({
            sliderInput(inputId = "sli_val1",
                        label = "values", min = 0, max = 100,
                        value = c(25, 75) )
        })
        setProgress(value=1, detail="Complete")
    })
}

shinyApp(ui = ui, server = server)

但是,当我将uiOutput移动到menuItem( )中时,输出不再呈现:

ui <- dashboardPage(
    dashboardHeader(),

    dashboardSidebar(
        sidebarMenu(
            menuItem(text = "data options",
                     checkboxGroupInput(inputId = "cbg_group1", label = "group 1",
                                        choices = c("some","check","boxes","to","choose","from") ),
                     uiOutput("sli_val1"),
                     checkboxGroupInput(inputId = "cbg_group2", label = "group 2",
                                        choices = c("another","set","of","check","boxes") )
                             ),
            menuItem(text = "another tab")
            )
    ),
    dashboardBody()
)

推荐答案

首先,我会将uiOutput("sli_val1")改为uiOutput("out_sli_val1"),以防止ID重复。

关于您的问题:当SHILINE遍历文档并呈现/绑定所有可能的输出时,这是一件奇怪的事情。默认操作是忽略所有隐藏的输出元素-这意味着不会完全忽略(输出"sli_val1"是正确的),但是它们的功能被挂起,不允许呈现任何子元素。

所以问题是,在启动时,此输出隐藏在子项树中,从那里开始被忽略。

可以通过调用

取消设置此支撑行为来完成修复
outputOptions(output, "out_sli_val1", suspendWhenHidden = FALSE)

但是如何以及在哪里呢?必须在运行"数据加载"之前设置此选项。但是,如果output$out_sli_val1没有分配给它(ISNULL),它将抛出错误。为了避免这种情况,可以初始化一个空的UI块,该块在"数据加载"时被覆盖。

以下是额外2行代码(以及修改后的输出ID)的最小修复:

library(shiny)
library(shinydashboard)

ui <- dashboardPage(
  dashboardHeader(),
  dashboardSidebar(
    sidebarMenu(
      menuItem(text = "data options",
        checkboxGroupInput(inputId = "cbg_group1", label = "group 1",
                           choices = c("some","check","boxes","to","choose","from") ),
        uiOutput("out_sli_val1"),
        checkboxGroupInput(inputId = "cbg_group2", label = "group 2",
                           choices = c("another","set","of","check","boxes") )
      ),
      menuItem(text = "another tab")
    )
  ),
  dashboardBody()
)

server <- function(input, output, session){
  output$out_sli_val1 <- renderUI({})
  outputOptions(output, "out_sli_val1", suspendWhenHidden = FALSE)

  withProgress(message = "loading page", value=0.1, {
    ## simulate loading some data
    Sys.sleep(3)

    ## slider input
    output$out_sli_val1 <- renderUI({
      sliderInput(inputId = "sli_val1", label = "values", min = 0, max = 100, value = c(25, 75) )
    })

    setProgress(value=1, detail="Complete")
  })
}

shinyApp(ui = ui, server = server)

这篇关于R SHINY-ui输出不在menuItem内渲染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!

07-22 23:11
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