Could not find a tree control for the tree

Question

I am facing an error for sample code I am using angular 6 and angular material for application design:

<mat-tree>
    <mat-tree-node> parent node </mat-tree-node>
</mat-tree>

Error Message:

Error: Could not find a tree control for the tree

any help much appreciated.

Answer 1

The documentation on Material Angular is not super clear about it... You need tho specifie a [treeControl]="nestedTreeControl" of the type NestedTreeControl<FileNode>;

If you go to Material Angular Tree Component and check the code you will understand easily.

Answer 2

In case you really want to work with a flat tree then this error also appears when you accidentally use <mat-nested-tree-node> instead of <mat-tree-node>.