Expand/Collapse buttons plus rowcounts and totals for rowGroups in DT::datatable

expand_collapse_datatable.R

library(shiny)

ui <- fluidPage(
  titlePanel("Expand/Collapse DataTable"),
  mainPanel(
    fluidRow(
      column(6, DT::dataTableOutput("tbl")),
      column(6, DT::dataTableOutput("tbl2"))
    )
  )
)

## start collapsed
callback_js <- DT::JS(
  "table.on('click', 'tr.dtrg-group', function () {",
  "  var rowsCollapse = $(this).nextUntil('.dtrg-group');",
  "  $(rowsCollapse).toggleClass('hidden');",
  "});",
  "table.on('init', () => $('.dtrg-group').trigger('click'))"
)

server <- function(input, output) {

  set.seed(1)
  d <- data.frame(Label = c("A", "A", "B", "B", "B", "C", "C", "C", "C"),
                  Value = sample(9))

  # Use the ID of the table in the JS. In this example, the first table is DataTables_Table_1
  output$tbl <- DT::renderDT({
    DT::datatable(
      d,
      extensions = c("RowGroup", "Buttons"),
      options = list(
        rowGroup = list(dataSrc = 1,
                        startRender = DT::JS("function(rows, group) {
                          var nrows = 0;
                          var total = 0;
                          rows.rows().data().filter(function(value, index) {
                            nrows += value[1] === group ? 1 : 0;
                            total += value[1] === group ? value[2] : 0;
                          });
                          return group + ' (' + nrows + ' rows; total value: ' + total + ')';
                        }")
                        ),
        pageLength = 20,
        dom = 'Bfrtlip',
        buttons = list(
          list(extend = "",
               text = 'Expand <span class="glyphicon glyphicon-plus"></span>',
               action = DT::JS("() => {
                                $('#DataTables_Table_1').find('.hidden').removeClass('hidden');
                             }")
          ),
          list(extend = "",
               text = 'Collapse <span class="glyphicon glyphicon-minus"></span>',
               action = DT::JS("() => {
                               $('#DataTables_Table_1').find('.even').addClass('hidden');
                               $('#DataTables_Table_1').find('.odd').addClass('hidden');
                               }")
          )
        )
      ),
      callback = callback_js,
      selection = 'none',
      escape = FALSE
    )
  })

  output$tbl2 <- DT::renderDT({
    DT::datatable(
      d,
      extensions = c("RowGroup"),
      options = list(
        rowGroup = list(dataSrc = 1)
      ),
      callback = callback_js,
      selection = 'none',
      escape = FALSE
    )})
}

# Run the application
shinyApp(ui = ui, server = server)

I couldn't find the way to do this documented anywhere so once I figured it out, I thought I'd share.

• Group rows by a column
• Collapse/Expand all grouped rows
• Add row counts and totals to the group headers

Screen.Recording.2023-05-03.at.1.59.26.pm.mov

Known limitations:

• To collapse/expand, this just adds the 'hidden' class to any element of class 'odd' or 'even' (or entirely removes the 'hidden' class from any element of class 'hidden') - this isn't specific to any one table or element, so take care if anything else has that class Table ID can now be specified which limits the operations to that table.

Screen.Recording.2023-05-03.at.4.09.22.pm.mov

Update: Use Array.from() to make the hid HTMLCollection non-lazy otherwise when the DOM is updated each iteration, the rows with 'hidden' class won't align.

Additional update: using jQuery .find('.hidden').removeClass('hidden') works even better.