Tree controls are one of the most popular ways to represent hierarchical information in web interfaces—they provide a means to deliver deeply nested, multi-level content in a compact space, and allow users to selectively expand and collapse nodes to control which parts of the tree structure to display. A tree control is often used as:
• A navigation component for websites with deeply nested structures, like ecommerce sites with a wide range and depth of product organization
• A data table with rows that can be expanded or collapsed, like in the project management tool Microsoft Project
• Navigation for a web application with hierarchical folders, like an email system or RSS reader.
A tree is essentially a series ...