在rCharts中单击绘图列时打印类别名称

Question

我试图在点击列时获取类别名称。我已经实现了以下代码，但它似乎不起作用。我做错了什么？

library(shiny)
library(rCharts)


ui <- fluidPage(

  showOutput("chart", lib="highcharts"),
  textOutput("check")
)


server <- function(input, output){
  output$chart <- renderChart2({
    p1 <- rCharts:::Highcharts$new()
    p1$chart(type = "column", width = 400, height = 400)
    p1$title(text = "Iris")
    p1$xAxis(categories = colnames(t(iris[1:4])), title = list(text = "Categories"))
    p1$yAxis(title = list(text = "Length"))
    p1$data(as.data.frame(iris[2,1:4]))

    p1$plotOptions(events = list(click = "#! function() {Shiny.onInputChange('click', {
                                                           x: this.data[1]                                                    
  })
} !#" ))


return(p1)

})



 output$check <- renderText(paste0(input$hcClicked$x))

}

shinyApp(ui =ui, server = server)