How to hide/show a column of a child table of a DT table?

Question

Assume you have a DT table with child tables in a Shiny app, as in this discussion for example (the method to make the child tables is taken from here). How can one hide/show a column of a child table?

Answer 1

Here is a way. The user selects the index of a child table, then selects the index of a column of this child table, and then clicks the button to hide/show this column. The rest of the code is taken from the discussion linked in the OP; in particular, the stuff with the checkboxes, which is not related to the present question.

library(DT)
library(shiny)

shinyCheckbox <- function(id, values) {
  inputs <- character(length(values))
  for(i in seq_along(inputs)) {
    inputs[i] <- 
      as.character(
        checkboxInput(paste0(id, i), label = NULL, value = values[i], width = "20px")
      )
  }
  inputs
}

NestedData <- function(dat, children){
  stopifnot(length(children) == nrow(dat))
  g <- function(d){
    if(is.data.frame(d)){
      purrr::transpose(d)
    }else{
      purrr::transpose(NestedData(d[[1]], children = d$children))
    }
  }
  subdats <- lapply(children, g)
  oplus <- ifelse(lengths(subdats), "&oplus;", "") 
  cbind(" " = oplus, dat, "_details" = I(subdats), 
        stringsAsFactors = FALSE)
}

dat <- data.frame(
  Sr = c(1.5, 2.3),
  Description = c("A - B", "X - Y")
)
## details of row 1
subdat1 <- data.frame(
  Chromosome = c("chr18","chr4"),
  SNP = c("rs2","rs3"),
  YN = c(TRUE, FALSE),
  stringsAsFactors = FALSE
)
subdat1$check <- shinyCheckbox("check", subdat1$YN)

## details of row 2
subdat2 <- data.frame(
  Chromosome = c("chr19","chr20"), 
  SNP = c("rs3","rs4"),
  YN = c(TRUE, FALSE),
  stringsAsFactors = FALSE
)
subdat2$check <- shinyCheckbox("check", subdat2$YN)

Dat <- NestedData(dat, list(subdat1, subdat2))

## whether to show row names
rowNames = FALSE
colIdx <- as.integer(rowNames)

## the callback
parentRows <- which(Dat[,1] != "")
callback <- JS(
  sprintf("var parentRows = [%s];", toString(parentRows-1)),
  sprintf("var j0 = %d;", colIdx),
  "var nrows = table.rows().count();",
  "for(let i = 0; i < nrows; ++i){",
  "  var $cell = table.cell(i,j0).nodes().to$();",
  "  if(parentRows.indexOf(i) > -1){",
  "    $cell.css({cursor: 'pointer'});",
  "  }else{",
  "    $cell.removeClass('details-control');",
  "  }",
  "}",
  "",
  "// --- make the table header of the nested table --- //",
  "var formatHeader = function(d, childId){",
  "  if(d !== null){",
  "    var html = ", 
  "      '<table class=\"display compact hover\" ' + ",
  "      'style=\"padding-left: 30px;\" id=\"' + childId + ", 
  "      '\"><thead><tr>';",
  "    var data = d[d.length-1] || d._details;",
  "    for(let key in data[0]){",
  "      html += '<th>' + key + '</th>';",
  "    }",
  "    html += '</tr></thead></table>'",
  "    return html;",
  "  } else {",
  "    return '';",
  "  }",
  "};",
  "",
  "// --- row callback to style rows of child tables --- //",
  "var rowCallback = function(row, dat, displayNum, index){",
  "  if($(row).hasClass('odd')){",
  "    $(row).css('background-color', 'papayawhip');",
  "    $(row).hover(function(){",
  "      $(this).css('background-color', '#E6FF99');",
  "    }, function(){",
  "      $(this).css('background-color', 'papayawhip');",
  "    });",
  "  } else {",
  "    $(row).css('background-color', 'lemonchiffon');",
  "    $(row).hover(function(){",
  "      $(this).css('background-color', '#DDFF75');",
  "    }, function(){",
  "      $(this).css('background-color', 'lemonchiffon');",
  "    });",
  "  }",
  "};",
  "",
  "// --- header callback to style header of child tables --- //",
  "var headerCallback = function(thead, data, start, end, display){",
  "  $('th', thead).css({",
  "    'border-top': '3px solid indigo',", 
  "    'color': 'indigo',",
  "    'background-color': '#fadadd'",
  "  });",
  "};",
  "",
  "// --- make the datatable --- //",
  "var formatDatatable = function(d, childId){",
  "  var data = d[d.length-1] || d._details;",
  "  var colNames = Object.keys(data[0]);",
  "  var columns = colNames.map(function(x){",
  "    return {data: x.replace(/\\./g, '\\\\\\.'), title: x};",
  "  });",
  "  var id = 'table#' + childId;",
  "  var subtable;",
  "  if(colNames.indexOf('_details') === -1){",
  "    subtable = $(id).DataTable({",
  "      'data': data,",
  "      'columns': columns,",
  "      'autoWidth': true,",
  "      'deferRender': true,",
  "      'info': false,",
  "      'lengthChange': false,",
  "      'ordering': data.length > 1,",
  "      'order': [],",
  "      'paging': false,",
  "      'scrollX': false,",
  "      'scrollY': false,",
  "      'searching': false,",
  "      'sortClasses': false,",
  "      'rowCallback': rowCallback,",
  "      'headerCallback': headerCallback,",
  "      'columnDefs': [{targets: '_all', className: 'dt-center'}]",
  "    });",
  "  } else {",
  "    subtable = $(id).DataTable({",
  "      'data': data,",
  "      'columns': columns,",
  "      'autoWidth': true,",
  "      'deferRender': true,",
  "      'info': false,",
  "      'lengthChange': false,",
  "      'ordering': data.length > 1,",
  "      'order': [],",
  "      'paging': false,",
  "      'scrollX': false,",
  "      'scrollY': false,",
  "      'searching': false,",
  "      'sortClasses': false,",
  "      'rowCallback': rowCallback,",
  "      'headerCallback': headerCallback,",
  "      'columnDefs': [", 
  "        {targets: -1, visible: false},", 
  "        {targets: 0, orderable: false, className: 'details-control'},", 
  "        {targets: '_all', className: 'dt-center'}",
  "      ]",
  "    }).column(0).nodes().to$().css({cursor: 'pointer'});",
  "  }", # THIS IS THE CODE I ADDED TO DEAL WITH THE CHECKBOXES:
  "  $(id).on('click', '[id^=check]', function(){",
  "    var id = this.getAttribute('id');",
  "    var i = parseInt(/check(\\d+)/.exec(id)[1]);",
  "    var value = $(this).prop('checked');",
  "    subtable.cell(i-1, 2).data(value).draw();",
  "    Shiny.setInputValue('update', {child: childId, row: i, value: value});",
  "  });",
  "};",
  "",
  "// --- display the child table on click --- //",
  "// array to store id's of already created child tables",
  "var children = [];", 
  "table.on('click', 'td.details-control', function(){",
  "  var tbl = $(this).closest('table'),",
  "      tblId = tbl.attr('id'),",
  "      td = $(this),",
  "      row = $(tbl).DataTable().row(td.closest('tr')),",
  "      rowIdx = row.index();",
  "  if(row.child.isShown()){",
  "    row.child.hide();",
  "    td.html('&oplus;');",
  "  } else {",
  "    var childId = tblId + '-child-' + rowIdx;",
  "    if(children.indexOf(childId) === -1){", 
  "      // this child has not been created yet",
  "      children.push(childId);",
  "      row.child(formatHeader(row.data(), childId)).show();",
  "      td.html('&CircleMinus;');",
  "      formatDatatable(row.data(), childId, rowIdx);",
  "    }else{",
  "      // this child has already been created",
  "      row.child(true);",
  "      td.html('&CircleMinus;');",
  "    }",
  "  }",
  "});")

js <- paste(
    'var i = $("#child").val() - 1;',
    'var tbl = $("#DataTables_Table_0-child-" + i).DataTable();',
    'var col = tbl.column($("#column").val() - 1);',
    'var visible = col.visible();',
    'col.visible(!visible);'
  )

ui <- fluidPage(
  br(),
  splitLayout(
    numericInput("child", "Child table", value = 1, min = 1, step = 1),
    numericInput("column", "Column", value = 1, min = 1, step = 1),
    actionButton(
      "hs", "Hide/show this column",
      onclick = js
    )
  ),
  br(),
  actionButton("print", "Print 'YN' columns of child tables"),
  br(),
  DTOutput("dtable")
)

server <- function(input, output, session) {
  output[["dtable"]] <- renderDT({
    datatable(
      Dat, 
      callback = callback, rownames = rowNames, escape = -colIdx-1,
      selection = "none",
      options = list(
        paging = FALSE,
        searching = FALSE,
        columnDefs = list(
          list(
            visible = FALSE, 
            targets = ncol(Dat)-1+colIdx
          ),
          list(
            orderable = FALSE, 
            className = "details-control", 
            targets = colIdx
          ),
          list(
            className = "dt-center", 
            targets = "_all"
          )
        )
      )
    )
  })
  
  observeEvent(input[["update"]], {
    print(input$update)
    child <- 
      stringr::str_extract(input[["update"]][["child"]], "\\d+$")
    row <- as.integer(input[["update"]][["row"]])
    value <- input[["update"]][["value"]]
    if(child == "0") {
      subdat1[row, "YN"] <<- value
    } else if(child == "1") {
      subdat2[row, "YN"] <<- value
    }
  })
  
  observeEvent(input[["print"]], {
    print(subdat1$YN)
    print(subdat2$YN)
  })
}

shinyApp(ui, server)