Wijmo interops for popular frameworks allow you to define custom content for MultiRow cells declaratively, by using each frameworks' own template markup in conjunction with Wijmo's MultiRowCellTemplate class.
Such templates may include arbitrary components and HTML elements, with property and event bindings. All types of grid cells can be defined using templates (data cells, header cells, editors, etc).
This sample shows a grid with the templates for all cell types. The templates can be dynamically enabled or disabled by toggling the checkboxes.