FORCDK-TREE-004
Thrown by forty-cdk/tree.
[forty-cdk/tree] FORCDK-TREE-004: [forTreeNodeDragHandle] must be used inside a [forTreeNodeDrag] element.
Cause
No FOR_TREE_NODE_DRAG_CONTEXT provider is visible from [forTreeNodeDragHandle]. Angular resolves a directive's dependencies at the template's declaration site rather than where it is stamped, so a piece declared in an ng-template outside the root resolves nothing even when it renders inside it.
Fix
Move [forTreeNodeDragHandle] inside a [forTreeNodeDrag] element, declaring any ng-template it lives in there too.