Guides

Expanding nodes on init

A common use case is to start with the tree expanded completely.
You can achieve this by calling treeModel.expandAll() after view init:

<tree-root #tree [nodes]="nodes"></tree-root>

@Component {
  nodes = [...];
  @ViewChild('tree') tree;

  ngAfterViewInit() {
    this.tree.treeModel.expandAll();
  }
}

Or to expand / activate specific nodes:

<tree-root #tree [nodes]="nodes"></tree-root>

@Component {
  nodes = [...];
  @ViewChild('tree') tree;

  ngAfterViewInit() {
    const someNode = this.tree.treeModel.getNodeById('someId');
    someNode.expand();
           
    const firstRoot = this.tree.treeModel.roots[0];
    firstRoot.setActiveAndVisible();
  }
}