闪亮应用程序中的Rblpapi订阅功能

我试图开发一个简单的闪亮的应用程序，打印最新的欧元价格

library(shiny)

ui <- basicPage(

  verbatimTextOutput(outputId = "roll", placeholder = TRUE)

)

server <- function(input, output) {

  Rblpapi::blpConnect()
  last_print <- reactiveVal(value = 1)

  Rblpapi::subscribe(securities = "EUR Curncy", fields = "LAST_PRICE", fun = function(x) last_print(x))

  output$roll <- renderPrint({
    last_print()$data$LAST_PRICE
  })
} 

shinyApp(ui = ui, server = server)

库（闪亮）
用户界面