如何在R Shiny中返回聚焦元素的ID？

install.packages("shinyjs")

library(shiny)
library(shinyjs)

ui <- fluidPage(
  useShinyjs(), # 添加shinyjs支持
  textInput("input1", "输入框1"),
  textInput("input2", "输入框2"),
  actionButton("button", "获取聚焦元素ID")
)

server <- function(input, output, session) {
  observeEvent(input$button, {
    focused_element_id <- getActiveElement()$name
    showModal(modalDialog(
      title = "聚焦元素ID",
      easyClose = TRUE,
      footer = NULL,
      textOutput(focused_element_id)
    ))
  })
}

shinyApp(ui, server)