useShinydashboardPlus()

if (interactive()) {

library(shiny)
library(shinydashboard)
library(shinydashboardPlus)
library(shinyWidgets)


# example taken from ?box

ui <- fluidPage(
  tags$h2("Classic shiny"),

  # use this in non shinydashboardPlus app
  useShinydashboardPlus(),
  setBackgroundColor(color = "ghostwhite"),

  # boxPlus
  box(
   title = "Improved box",
   closable = TRUE,
   width = 12,
   status = "warning",
   solidHeader = FALSE,
   collapsible = TRUE,
   label = boxLabel(
     text = 1,
     status = "danger",
     style = "circle"
   ),
   dropdownMenu = boxDropdown(
     boxDropdownItem("Link to google", href = "http://www.google.com"),
     boxDropdownItem("item 2", href = "#"),
     dropdownDivider(),
     boxDropdownItem("item 3", href = "#", icon = icon("th"))
   ),
   sidebar = boxSidebar(
     startOpen = TRUE,
     id = "mycardsidebar",
     sliderInput(
       "obs",
       "Number of observations:",
       min = 0,
       max = 1000,
       value = 500
     )
   ),
   plotOutput("distPlot")
  ),

  br(),

  # extra elements
  fluidRow(
  column(
   width = 6,
   timelineBlock(
    reversed = FALSE,
    timelineEnd(color = "red"),
    timelineLabel(2018, color = "teal"),
    timelineItem(
      title = "Item 1",
      icon = icon("gears"),
      color = "olive",
      time = "now",
      footer = "Here is the footer",
      "This is the body"
    ),
    timelineItem(
      title = "Item 2",
      border = FALSE
    ),
    timelineLabel(2015, color = "orange"),
    timelineItem(
      title = "Item 3",
      icon = icon("paint-brush"),
      color = "maroon",
      timelineItemMedia(image = "https://placehold.it/150x100"),
      timelineItemMedia(image = "https://placehold.it/150x100")
    ),
    timelineStart(color = "purple")
   )
  ),
  column(
   width = 6,
   box(
     title = "Box with boxPad containing inputs",
     status = "warning",
     width = 12,
     fluidRow(
       column(
         width = 6,
         boxPad(
           color = "gray",
           sliderInput(
             "obs2",
             "Number of observations:",
             min = 0, max = 1000, value = 500
           ),
           checkboxGroupInput(
             "variable",
             "Variables to show:",
             c(
               "Cylinders" = "cyl",
               "Transmission" = "am",
               "Gears" = "gear"
             )
           ),

           knobInput(
             inputId = "myKnob",
             skin = "tron",
             readOnly = TRUE,
             label = "Display previous:",
             value = 50,
             min = -100,
             displayPrevious = TRUE,
             fgColor = "#428BCA",
             inputColor = "#428BCA"
           )
         )
       ),
       column(
         width = 6,
         plotOutput("distPlot2", height = "200px"),
         tableOutput("data")
       )
     )
    )
   )
  )
)

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

  output$distPlot <- renderPlot({
   hist(rnorm(input$obs))
  })

  output$distPlot2 <- renderPlot({
    hist(rnorm(input$obs2))
  })

  output$data <- renderTable({
    head(mtcars[, c("mpg", input$variable), drop = FALSE])
  }, rownames = TRUE)

}

shinyApp(ui, server)

}