This JavaScript TreeView example demonstrates the template functionalities of the TreeView. Select the root node by clicking on it, or expand the root node and select the customized child node.
The TreeView component has an option to customize the node structure through the nodeTemplate property, so that the tree node can be formed with any custom structure. In this demo, the node is formed as like webmail with folder name and number of unread messages. For more information, you can refer to the Templates section from the documentation.