Null Plotly Object

app.R

library("shiny")
library("plotly")

set.seed(100)
d <- diamonds[sample(nrow(diamonds), 1000), ]


ui <- fluidPage(

   titlePanel("Null Plotly Object"),

   sidebarLayout(
      sidebarPanel(
         checkboxGroupInput("cuts", "Cut", choices = sort(unique(d$cut)))
      ),

      mainPanel(
         plotlyOutput("distPlot")
      )
   )
)

server <- function(input, output) {

  plot_dat <- reactive({
    shiny::validate(
      need(input$cuts, "Select a cut")
    )
    d[d$cut %in% input$cuts, ]
  })

   output$distPlot <- renderPlotly({
     plot_ly(plot_dat(), x = ~carat, y = ~price, color = ~carat, type = "scatter",
             mode = "markers", size = ~carat, text = ~paste("Clarity: ", clarity))
   })
}

shinyApp(ui = ui, server = server)