/// within widget _create()
tihs.dataTable = this.$dataTable.dataTable({
    order: [[1, "asc"]],
    columns: [
        {
            data: null,
            orderable: false,
            defaultContent: "",
            createdCell: this._createExpandCell.bind(this)
        },
        // ...
        // data columns
        // ...
        {
            data: null,
            orderable: false,
            defaultContent: "",
            createdCell: this._createControlCell.bind(this)
        }
    ],
    serverSide: true,
    deferLoading: 0,
    ajax: function (data, callback, settings) {
        DemoDataService.GetData("Snapshots", callback, data);
    }.bind(this)
});

/// widget methods
_createExpandCell: function (cell, cellData, rowData, rowIndex, colIndex) {
    $(cell)
        .append($("<span></span>")
            .ExpandButton({
                 isExpanded: false,
                 expanded: function() {
                    let dataTableRow = this.dataTable.api().row(rowIndex);
                    if (dataTableRow.child() == null) {
                        dataTableRow.child("<div></div>").show();
                        dataTableRow.child().children().html("FACTS TABLE PENDING");
                    }
                    else {
                        dataTableRow.child.show();
                    }
                }.bind(this),
                collapsed: function () {
                    this.dataTable.api().row(rowIndex).child.hide();
                }.bind(this)
            }));
},
_createControlCell: function (cell, cellData, rowData, rowIndex, colIndex) {
    $(cell)
        .append($("<span></span>")
            .button({
                text: false,
                icons: {
                    primary: "ui-icon-pencil"
                }
            })
            .click(function () {
                Dialogs.EditSnapshot.Open(rowData, function (event, result) {
                    if ((result.result === "save") || (result.result === "retake"))
                        this.dataTable.api().row(rowIndex).data(result.snapshot);
                }.bind(this));
            }.bind(this)));
},