闪亮的仪表板选项冻结

Question

我测试了一个基本的闪亮仪表板应用程序，其中输入小部件放置在一个选项卡中，而结果呈现在另一个选项卡中。第一次运行没问题，但在第二个选项卡中显示结果后，无法切换回第一个选项卡来更改输入值。

library(shiny)
library(shinydashboard)
library(tidyverse)

myDF <- data.frame( let = letters, id = seq(1, length(letters)))

myHead <- dashboardHeader(
    title = "Trial"
)

mySideB <- dashboardSidebar(
    menuItem(
        "tab1", tabName = "tab1"
    ),
    menuItem(
        "tab2", tabName = "tab2"
    )
)


myBody <- dashboardBody(
    tabItems(
        tabItem(
            tabName = "tab1",
            box(
                title = "Selection",
                selectInput(
                    inputId = "sel1",
                    label = "Select a letter",
                    choices = myDF$let,
                    selected = ""
                )
            )
        ),
        tabItem(
            tabName = "tab2",
            box(
                title = "Results",
                textOutput(outputId = "res")
            )
        )
    )
)

ui <- dashboardPage(
    myHead,
    mySideB,
    myBody
)

server <- function(input, output) {
    
    filtDF <- reactive({
        myDF %>% 
            filter(let %in% input$sel1) %>% 
            select(id) %>% 
            as.character()
    })
    
    output$res <- renderText({ filtDF() })
    
}

shinyApp(ui = ui, server = server)

我阅读了几个主题，并测试了已发布的示例，但很简单，我看不出上面的代码有什么问题。有什么建议吗？

Answer 1

    mySideB <- dashboardSidebar(
    sidebarMenu(
        menuItem(
            "tab1", tabName = "tab1"
        ),
        menuItem(
            "tab2", tabName = "tab2"
        )
    )
)