Render datatable with sparklines in Shiny

[Grant]

I want to include sparklines in a shiny DT. It works fine in the RStudio viewer but in Shiny the sparklines are not rendered. Here is a minimal example. I suspect the problem has to do with adding the sparkline dependencies. It's not clear to me how to use 'spk_add_deps()' in shiny, hence my hack of adding a dummy sparkline outside of the DT to get the dependencies attached.

 

# dependencies
  require(sparkline)
  require(DT)
  require(shiny)


# create data with sparklines
  spark_data <- data.frame(
    id = c('spark1', 'spark2'),
    spark = c(
      spk_chr(values = 1:3, elementId = 'spark1'),
      spk_chr(values = 3:1, elementId = 'spark2')
    )
  )
 
# render in RStudio viewer (this works)
  tbl <- datatable(spark_data, escape = FALSE)
  spk_add_deps(tbl)


# render in Shiny (no sparklines rendered in DT)
  ui <- fluidPage(
      sparklineOutput("test_spark"),
      dataTableOutput("tbl")
  )
 
  server <- function(input, output) {
    # sparkline outside DT (works fine) - this also ensures sparkline dependencies are attached
      output$test_spark <- renderSparkline(sparkline(1:3))
   
    # sparkline inside DT (does not render)
      output$tbl <- renderDataTable(
        expr = spark_data,
        escape = FALSE
      )
  }
 
  shinyApp(ui = ui, server = server)