Method isExpanded

src/cdk/tree/tree.ts:630–635

Whether the data node is expanded or collapsed. Returns true if it's expanded.

(dataNode: T)

  /** Whether the data node is expanded or collapsed. Returns true if it's expanded. */
  isExpanded(dataNode: T): boolean {
    return !!(
      this.treeControl?.isExpanded(dataNode) ||
      this._expansionModel?.isSelected(this._getExpansionKey(dataNode))
    );
  }

  /** If the data node is currently expanded, collapse it. Otherwise, expand it. */
  toggle(dataNode: T): void {