Controlling the Expanded State
The Grid enables you to define and persist the expanded state of its master-detail rows.
The Grid provides a built-in directive to simplify controlling the expanded state of a master-detail row.
The directive takes the key name or a function that returns the key value for a given data item as argument. The item key will be stored in the expandedDetailKeys collection.This approach provides you with full control over the expanded details functionality—for example, it allows you to specify initially expanded items, manually update the collection, and so on.
The following example demonstrates using the directive.
The Grid exposes the isDetailExpanded function to control and determines if a specific master-detail row is expanded.