如何在Shiny动态UI中获取dataTable的单元格点击事件？

问题根源 #

你当前代码里，动态表格是用renderUI套着renderDT输出的——这种写法会导致DT表格的实际DOM元素ID不是你定义的dynamic，而是DT内部自动生成的随机ID，所以input$dynamic_cells_selected这个输入对象根本不存在，自然拿不到单元格选择事件。

最简修正方案 #

别用renderUI中转，直接用renderDT对应DTOutput输出动态表格就行。哪怕需要根据条件动态切换表格内容，也只需要在renderDT里写逻辑判断，不需要额外套renderUI。

修正后的完整代码 #

library(shiny)
library(DT)

ui <- fluidPage(
  textOutput("out"),
  # 把uiOutput换成DTOutput
  DTOutput("dynamic"),
  DTOutput("normal")
)

server <- function(input, output, session) {
  # 去掉renderUI包裹，直接用renderDT输出到dynamic
  output$dynamic <- renderDT(
    mtcars,
    rownames = FALSE,
    selection = list(mode = "single", target = "cell"),
    options   = list(dom  = "t"     , pageLength = 5)
  )

  output$normal <- renderDT(
    iris,
    rownames = FALSE,
    selection = list(mode = "single", target = "cell"),
    options   = list(dom  = "t"     , pageLength = 5)
  )

  output$out <- renderText({
    paste(
      "Normal",  paste(input$normal_cells_selected, collapse = " "), "\n",
      "Dynamic", paste(input$dynamic_cells_selected, collapse = " ")
    )
  })
}

shinyApp(ui, server)

特殊场景补充 #

如果确实需要用uiOutput动态生成（比如要在表格和其他组件之间切换），可以手动给DT指定固定ID：

# UI部分保留uiOutput
ui <- fluidPage(
  textOutput("out"),
  uiOutput("dynamic"),
  DTOutput("normal")
)

server <- function(input, output, session) {
  output$dynamic <- renderUI({
    # 手动指定DT输出的ID为dynamic_table
    DTOutput("dynamic_table")
  })
  
  # 针对指定的ID渲染表格
  output$dynamic_table <- renderDT(
    mtcars,
    rownames = FALSE,
    selection = list(mode = "single", target = "cell"),
    options   = list(dom  = "t"     , pageLength = 5)
  )

  output$normal <- renderDT(
    iris,
    rownames = FALSE,
    selection = list(mode = "single", target = "cell"),
    options   = list(dom  = "t"     , pageLength = 5)
  )

  # 此时捕获动态表格事件要使用指定ID对应的输入对象
  output$out <- renderText({
    paste(
      "Normal",  paste(input$normal_cells_selected, collapse = " "), "\n",
      "Dynamic", paste(input$dynamic_table_cells_selected, collapse = " ")
    )
  })
}

shinyApp(ui, server)

这种写法仅适合复杂的动态组件切换场景，一般优先用第一种方案更简洁。

内容的提问来源于stack exchange，提问作者pietrodito