在Shiny DT中单击单元格旁边获取单元格值

Question

My Shiny App在DT又名DataTables中渲染DT帧。我知道如何通过添加后缀获得点击单元格的值：

_cell_clicked

例如：

> print(unlist(( input$renderMpaDtOutput_cell_clicked )))

返回命名列表对象：

row col value 1 9 3929

但我想在单击的单元格旁边获取单元格值（例如，在上面的坐标旁边：(row,col) = (1,9)）。

有什么想法吗？

Answer 1

只需将坐标添加到row和col值即可。获取用于创建数据表的table，获取input$dt_cell_clicked$row和$col并询问table[input$dt_cell_clicked$row + 1, input$dt_cell_clicked$col]，反之亦然。示例app：

library(shiny)

ui <- fluidPage(
 numericInput("x", "how many cells to the left/right?", min=-5, max=5, value=0),
 numericInput("y", "how many cells to the top/bottom?", min=-5, max=5, value=0),
 DT::dataTableOutput("dt"),
 uiOutput("headline"),
 verbatimTextOutput("shifted_cell")
)

server <- function(input, output) {

  output$headline <- renderUI({
    h3(paste0("You clicked value ", input$dt_cell_clicked$value, ". ", 
              input$x, " cells to the ", ifelse(input$x > 0, "right", "left"), " and ",
              input$y, " cells to the ", ifelse(input$y > 0, "bottom", "top"), " is:"))
  })
  # the value of the shifted cell
  output$shifted_cell <- renderPrint({
    mtcars[input$dt_cell_clicked$row + input$y, # clicked plus y to the bottom/top
           input$dt_cell_clicked$col + input$x] # clicked plus x to the left/right 
  })

  # the datatable
  output$dt <- DT::renderDataTable({
    DT::datatable(mtcars, select="none")})
}

shinyApp(ui, server)