ShinyDashboard：在默认主题和暗模式之间切换

Question

我使用this 教程将暗模式切换器引入我的应用程序。 我希望应用程序在未选中复选框时返回默认主题。 我在dashboardthemes 库中找不到“默认”主题，也找不到在shinyDashboardThemeDIY() 函数中使用的默认主题定义。 任何线索将不胜感激。

在一段可重现的代码下方（它在第一阶段完美运行，但当我取消选中复选框时没有任何反应：主题保持黑暗而不是再次变为白色和蓝色）

library(shiny)
library(shinydashboard)
library(dashboardthemes)

# Functions
uiDarkModeCheckBox <- function()
{
    ns <- NS("moduleChangeTheme")
    checkbox <- tagList(
        checkboxInput(
            inputId = ns("dbxChangeTheme"),
            label = "Dark Mode",
            value = FALSE
        )
    )
    
    return(checkbox)
}

uiChangeThemeOutput <- function()
{
    ns <- NS("moduleChangeTheme")
    themeOutput <- tagList(
        uiOutput(ns("uiChangeTheme"))
    )
    
    return(themeOutput)
}

serverChangeTheme <- function(input, output, session)
{
    observeEvent(
        input$dbxChangeTheme, 
        {
            output$uiChangeTheme <- renderUI({
                if (input$dbxChangeTheme == TRUE) {
                    uiChangeThemeOutput()
                    shinyDashboardThemes(theme = "grey_dark")
                }
            })
        }
    )
}

# UI
ui <- dashboardPage(dashboardHeader(),
                    dashboardSidebar(),
                    dashboardBody(
                        uiChangeThemeOutput(),
                            tabItem(tabName = "inputs_tab",
                                    uiDarkModeCheckBox(),
                            )
                    )

)

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

    callModule(module = serverChangeTheme, id = "moduleChangeTheme")
}

shinyApp(ui, server)

Answer 1

根据需要设置默认主题defaultTheme = "grey_light"。

 uiChangeThemeDropdown <- function(dropDownLabel = "Change Theme", defaultTheme = "grey_light")
  {
    changeThemeChoices <- c(
      "Blue gradient" = "blue_gradient",
      "Flat Red" = "flat_red",
      "Grey light" = "grey_light",
      "Grey dark" = "grey_dark",
      "OneNote" = "onenote",
      "Poor man's Flatly" = "poor_mans_flatly",
      "Purple gradient" = "purple_gradient"
    )