ShinydashBoard 呈现的 tabItem 未正确显示

Question

现在我在 shinydashboard 中遇到了 tabItem 的问题。我在侧边栏菜单中有一个菜单项，我想做的是当我点击动作按钮时，会添加一个新的菜单项和一个新的tabitem。但是，当我部署代码时，奇怪的是新渲染的tabitem内容只是将自己附加到第一个 tabitem。 我已经将 tabitem 放在 tabitems 中，但我仍然遇到这个问题。下面是代码：

library(shiny)
library(shinydashboard)

## ============================================ Define ui ==================================================

header1 <- dashboardHeader(
  title = "My Dynamic Menu"
) #dashboardHeader

# DYNAMIC UI
sidebar1 <- dashboardSidebar(
  sidebarMenu(
    menuItem('aa',tabName = 'aa')
  ) ,
  sidebarMenuOutput('bb')
) #dashboardSidebar
#
body1 <- dashboardBody(
  tabItems(
    tabItem(tabName = 'aa','aaa', actionButton('submit','Submit')),
    uiOutput('cc')
  ) #tabItems
) #dashboardBody

ui <- dashboardPage(header1, sidebar1, body1)

server <- function(input, output, session) {
  observeEvent(input$submit, {
    output$bb<-renderMenu({
      sidebarMenu(
        menuItem("Main", tabName = "main")
      )
    })
    
    output$cc<-renderUI({
      tabItem(tabName = "main",
              h2("Login"),
              textInput(inputId = "username1", label = "User name:", value = ""),
              passwordInput(inputId = "password1", label = "Password:"),
              actionButton(inputId = "loginbutton1", label = "Login")
      )
    })
  })
} #server
## ============================================ Run application ============================================
shinyApp(ui, server)

感谢谁能帮我解决这个问题。

Answer 1

我已经更新了您的示例，使其可以正常工作。我的解决方案是设置您的dashboardBody，就好像您的动态呈现的选项卡已经存在，并带有tabItem 调用。然后只需在新标签的内容上使用renderUI。 “主”菜单项不存在似乎并不重要，您仍然可以在正文中设置选项卡来处理将在服务器端呈现的菜单项。

我猜tabItems 只期望调用tabItem，所以在传递uiOutput 时你会得到意想不到的行为。

下面的代码应该会给你你期望的行为：

library(shiny)
library(shinydashboard)

## ============================================ Define ui ==================================================

header1 <- dashboardHeader(
    title = "My Dynamic Menu"
) #dashboardHeader

# DYNAMIC UI
sidebar1 <- dashboardSidebar(
    sidebarMenu(
        menuItem('aa',tabName = 'aa')
    ) ,
    sidebarMenuOutput('bb')
) #dashboardSidebar
#
body1 <- dashboardBody(
    tabItems(
        tabItem(tabName = 'aa','aaa', actionButton('submit','Submit')),
        tabItem(tabName = "main", uiOutput('cc')) # put a tabItem here
    ) #tabItems
) #dashboardBody

ui <- dashboardPage(header1, sidebar1, body1)

server <- function(input, output, session) {
    observeEvent(input$submit, {
        output$bb<-renderMenu({
            sidebarMenu(
                menuItem("Main", tabName = "main")
            )
        })
        
        output$cc<-renderUI({ #render just the content of your tab here
            tagList(
                h2("Login"),
                textInput(inputId = "username1", label = "User name:", value = ""),
                passwordInput(inputId = "password1", label = "Password:"),
                actionButton(inputId = "loginbutton1", label = "Login")   
            )
        })
    })
} #server
## ============================================ Run application ============================================
shinyApp(ui, server)