CellSelection

The CellSelection mixin extends upon the functionality of the Selection mixin
to provide selection at the cell level instead.

require([
    'dojo/_base/declare',
    'dgrid/OnDemandGrid',
    'dgrid/CellSelection'
], function (declare, OnDemandGrid, CellSelection) {
    var grid = new (declare([ OnDemandGrid, CellSelection ]))({
        selectionMode: 'single',
        // ...
    });
});

Differences from Selection mixin

• The selection object stores a nested hash, where the outer hash is
  keyed by item ID and the inner hashes are keyed by column ID.
• The dgrid-select and dgrid-deselect events still fire, but include a
  cells property containing an array of cell objects, rather than a rows
  property.
• Whereas Selection's select, deselect, and isSelected methods look up the
  passed argument via List's row method, CellSelection looks it up via Grid's
  cell method.
• The allowSelect method is passed a cell object instead of a row object.