如何将总计添加到 DT::datatable？

Question

我正在尝试将总计添加到数据表页脚。使用来自不同来源的代码，我使用 Shiny 编写了以下应用程序。问题是，当我运行它时，会出现以下消息：

“加工 ...”

并永远留在那里。

我的猜测是 JS() 代码，但无法调试。

library(shiny)
library(DT)
library(htmltools)

ui <- fluidPage(


  fluidRow(
    column(9, DT::dataTableOutput('withtotal'))
  )

)
server <- function(input, output, session) {

  # server-side processing
  mtcars2 = mtcars[, 1:8]
  #sketch <- htmltools::withTags(table(tableHeader(mtcars2), tableFooter(mtcars2)))

  sketch = htmltools::withTags(table(tableFooter(c("",0,0,0,0,0,0,0))))

 opts <- list( footerCallback = JS("function ( row, data, start, end, display ) {",
     "var api = this.api();",
     "var intVal = function ( i ) {",
      "return typeof i === 'string' ?",
       "i.replace(/[\\$,]/g, '')*1 :",
         "typeof i === 'number' ?",
         "i : 0;",
     "};",
     "if (api.column(COLNUMBER).data().length){",
       "var total = api",
       ".column( COLNUMBER )",
       ".data()",
       ".reduce( function (a, b) {",
         "return intVal(a) + intVal(b);",
       "} ) }",
     "else{ total = 0};",
     "if (api.column(COLNUMBER).data().length){",
       "var pageTotal = api",
       ".column( COLNUMBER, { page: 'current'} )",
       ".data()",
       ".reduce( function (a, b) {",
        " return intVal(a) + intVal(b);",
       "} ) }",
    "else{ pageTotal = 0};",
     "$( api.column(COLNUMBER).footer() ).html(",
       "'$'+pageTotal",
     ");",
   "}"))


  output$withtotal = DT::renderDataTable(DT::datatable(mtcars2,container = sketch, options = opts))      


}

options(shiny.error = browser)
# Run the application 
shinyApp(ui = ui, server = server)

Answer 1

这是一个没有使用 Shiny 的版本。我使用了与上面@gscott 相同的 JavaScript，但这是针对独立表的。我在 RMarkdown 文档中使用了它。我一直在努力解决这个问题的关键是container参数，它将页脚添加到表格中。

library(htmlwidgets)
library(DT)
library(htmltools)

sketch <- htmltools::withTags(table(
  tableHeader(colnames(mtcars)), 
  tableFooter(c(0,0,0,0,0,0,0,0,0,0,0,0))
))

jsCode <- "function(row, data, start, end, display) {
  var api = this.api(), data;
  total = api.column(7, {page: 'current'}).data().reduce( function(a, b) { return a + 
b}, 0);
  total2 = api.column(6, {page: 'current'}).data().reduce( function(a, b) { return a 
+ b}, 0);
  total3 = api.column(2, {page: 'current'}).data().reduce( function(a, b) { return a 
+ b}, 0);
  $( api.column(7).footer() ).html('Total: ' + total.toFixed(2));
  $( api.column(6).footer() ).html('Total: ' + total2.toFixed(2));
  $( api.column(2).footer() ).html('Total: ' + total3.toFixed(2))
  }"

DT::datatable(mtcars, container = sketch, options=list(scrollY=300, scrollX=TRUE, scroller=TRUE, footerCallback = JS(jsCode)))

Answer 2

看起来您正在使用我在闪亮的 DataTables 页脚回调总和中所做的相同示例程序 ，因此我对页脚回调问题的解决方案如下。这是我发现的最容易逐列操作的方法。

library(shiny)
library(DT)

ui <- fluidPage(

  title = 'Select Table Rows',

  hr(),

  h1('A Server-side Table'),

  fluidRow(
    column(9, DT::dataTableOutput('x3'))
  )

)


server <- function(input, output, session) {

  # server-side processing

  mtcars2 = mtcars[, 1:8]

  sketch <- htmltools::withTags(table(
                  class = "display",
                  style = "bootstrap",
                  tableHeader(colnames(mtcars2)),
                  tableFooter(colnames(mtcars2))
          ))

  output$x3 = DT::renderDataTable(DT::datatable(mtcars2,
                                                container = sketch,
                                                extensions = 'Buttons',
                                                options = list(
                                                  scrollX = TRUE,
                                                  scrollY = TRUE,
                                                  pageLength = 10,
                                                  order = list(list(1, 'asc')),
                                                  dom = 'Blrtip',
                                                  buttons = c('copy', 'csv', 'excel', 'pdf', 'print'),
                                                  footerCallback = JS(
       "function( tfoot, data, start, end, display ) {",
       "var api = this.api(), data;",
        "total = api.column( 1, { page: 'current'} ).data().reduce( function ( a, b ) {return a + b;} )",
        "total1 = api.column( 2, { page: 'current'} ).data().reduce( function ( a, b ) {return a + b;} )",
       "total2 = api.column( 3, { page: 'current'} ).data().reduce( function ( a, b ) {return a + b;} )",
        "total3 = api.column( 4, { page: 'current'} ).data().reduce( function ( a, b ) {return a + b;} )",
       "total4 = api.column( 5, { page: 'current'} ).data().reduce( function ( a, b ) {return a + b;} )",
        "total5 = api.column( 6, { page: 'current'} ).data().reduce( function ( a, b ) {return a + b;} )",
       "total6 = api.column( 7, { page: 'current'} ).data().reduce( function ( a, b ) {return a + b;} )",
        "total7 = api.column( 8, { page: 'current'} ).data().reduce( function ( a, b ) {return a + b;} )",
        "$( api.column( 1 ).footer() ).html(total.toFixed(2));
        $( api.column( 2 ).footer() ).html(total1.toFixed(2));
        $( api.column( 3 ).footer() ).html(total2.toFixed(2));
        $( api.column( 4 ).footer() ).html(total3.toFixed(2));
        $( api.column( 5 ).footer() ).html(total4.toFixed(2));
        $( api.column( 6 ).footer() ).html(total5.toFixed(2));
        $( api.column( 7 ).footer() ).html(total6.toFixed(2));
        $( api.column( 8 ).footer() ).html(total7.toFixed(2));",
        "}"
        ))
      ))
}

shinyApp(ui = ui, server = server)