This sample demonstrates the Header Template functionality in QueryBuilder component using DropDownList and Button components. In this sample, user can change the Condition using DropDownList component and adding rules, groups and deleting groups by using Button component.
This sample illustrates how to integrate HeaderTemplate in the QueryBuilder. This is used for creating custom user interface for the header with custom components and update the rule collection by using the component events.
More information about Query Builder can be found in this documentation section.