This sample demonstrates the Gantt header template feature. In this sample, custom icons have been shown in the column headers.
The Gantt provides a way to define a custom element in header element. The columns -> headerTemplate property accepts either string or HTML element`s ID value, which will be used as the template for the header cell. In this demo, we have rendered the customized template for all column headers. More information on the Essential® JS2 Gantt Chart can be found in this documentation section.