now works

src/Umbraco.Web.UI.Client/libs/repository/repository-tree-data-source.interface.ts

@@ -3,6 +3,5 @@ import type { DataSourceResponse } from '@umbraco-cms/models';
 
 export interface RepositoryTreeDataSource {
 	getRootItems(): Promise<DataSourceResponse<PagedEntityTreeItemModel>>;
-	getChildrenOf(parentKey: string): Promise<DataSourceResponse<PagedEntityTreeItemModel>>;
 	getItems(key: Array<string>): Promise<DataSourceResponse<EntityTreeItemModel[]>>;
 }

src/Umbraco.Web.UI.Client/libs/repository/tree-repository.interface.ts

@@ -7,11 +7,6 @@ export interface UmbTreeRepository {
 		error: ProblemDetailsModel | undefined;
 		asObservable?: () => Observable<EntityTreeItemModel[]>;
 	}>;
-	requestTreeItemsOf: (parentKey: string | null) => Promise<{
-		data: PagedEntityTreeItemModel | undefined;
-		error: ProblemDetailsModel | undefined;
-		asObservable?: () => Observable<EntityTreeItemModel[]>;
-	}>;
 	requestTreeItems: (keys: string[]) => Promise<{
 		data: Array<EntityTreeItemModel> | undefined;
 		error: ProblemDetailsModel | undefined;

src/Umbraco.Web.UI.Client/src/backoffice/settings/relation-types/repository/relation-type.repository.ts

@@ -66,23 +66,6 @@ export class UmbRelationTypeRepository implements UmbTreeRepository, UmbDetailRe
 		return { data, error, asObservable: () => this.#treeStore!.rootItems };
 	}
 
-	async requestTreeItemsOf(parentKey: string | null) {
-		await this.#init;
-
-		if (!parentKey) {
-			const error: ProblemDetailsModel = { title: 'Parent key is missing' };
-			return { data: undefined, error };
-		}
-
-		const { data, error } = await this.#treeSource.getChildrenOf(parentKey);
-
-		if (data) {
-			this.#treeStore?.appendItems(data.items);
-		}
-
-		return { data, error, asObservable: () => this.#treeStore!.childrenOf(parentKey) };
-	}
-
 	async requestTreeItems(keys: Array<string>) {
 		await this.#init;
 

src/Umbraco.Web.UI.Client/src/backoffice/settings/relation-types/repository/sources/relation-type.tree.server.data.ts

@@ -1,15 +1,14 @@
-import type { RepositoryTreeDataSource } from '../../../../../../libs/repository/repository-tree-data-source.interface';
 import { ProblemDetailsModel, RelationTypeResource } from '@umbraco-cms/backend-api';
 import { UmbControllerHostInterface } from '@umbraco-cms/controller';
 import { tryExecuteAndNotify } from '@umbraco-cms/resources';
 
 /**
- * A data source for the Document tree that fetches data from the server
+ * A data source for the RelationType tree that fetches data from the server
  * @export
- * @class DocumentTreeServerDataSource
- * @implements {DocumentTreeDataSource}
+ * @class RelationTypeTreeServerDataSource
+ * @implements {RelationTypeTreeDataSource}
  */
-export class RelationTypeTreeServerDataSource implements RepositoryTreeDataSource {
+export class RelationTypeTreeServerDataSource implements RelationTypeTreeDataSource {
 	#host: UmbControllerHostInterface;
 
 	// TODO: how do we handle trashed items?
@@ -46,9 +45,9 @@ export class RelationTypeTreeServerDataSource implements RepositoryTreeDataSourc
 	}
 
 	/**
-	 * Creates an instance of DocumentTreeServerDataSource.
+	 * Creates an instance of RelationTypeTreeServerDataSource.
 	 * @param {UmbControllerHostInterface} host
-	 * @memberof DocumentTreeServerDataSource
+	 * @memberof RelationTypeTreeServerDataSource
 	 */
 	constructor(host: UmbControllerHostInterface) {
 		this.#host = host;
@@ -57,37 +56,17 @@ export class RelationTypeTreeServerDataSource implements RepositoryTreeDataSourc
 	/**
 	 * Fetches the root items for the tree from the server
 	 * @return {*}
-	 * @memberof DocumentTreeServerDataSource
+	 * @memberof RelationTypeTreeServerDataSource
 	 */
 	async getRootItems() {
 		return tryExecuteAndNotify(this.#host, RelationTypeResource.getTreeRelationTypeRoot({}));
 	}
 
-	/**
-	 * Fetches the children of a given parent key from the server
-	 * @param {(string | null)} parentKey
-	 * @return {*}
-	 * @memberof DocumentTreeServerDataSource
-	 */
-	async getChildrenOf(parentKey: string | null) {
-		if (!parentKey) {
-			const error: ProblemDetailsModel = { title: 'Parent key is missing' };
-			return { error };
-		}
-
-		return tryExecuteAndNotify(
-			this.#host,
-			RelationTypeResource.getTreeRelationTypeChildren({
-				parentKey,
-			})
-		);
-	}
-
 	/**
 	 * Fetches the items for the given keys from the server
 	 * @param {Array<string>} keys
 	 * @return {*}
-	 * @memberof DocumentTreeServerDataSource
+	 * @memberof RelationTypeTreeServerDataSource
 	 */
 	async getItems(keys: Array<string>) {
 		if (keys) {

src/Umbraco.Web.UI.Client/src/backoffice/shared/components/tree/tree.element.ts

@@ -73,6 +73,7 @@ export class UmbTreeElement extends UmbLitElement {
 				.pipe(map((trees) => trees.find((tree) => tree.alias === this.alias))),
 			async (tree) => {
 				if (this._tree?.alias === tree?.alias) return;
+
 				this._tree = tree;
 				this.#provideTreeContext();
 			}

src/Umbraco.Web.UI.Client/src/core/mocks/data/relation-type.data.ts

@@ -1,5 +1,5 @@
 import { UmbEntityData } from './entity.data';
-import { createEntityTreeItem, createFolderTreeItem } from './utils';
+import { createEntityTreeItem } from './utils';
 import type { FolderTreeItemModel, RelationTypeResponseModel } from '@umbraco-cms/backend-api';
 
 // TODO: investigate why we don't get an entity type as part of the RelationTypeResponseModel
@@ -17,6 +17,7 @@ export const data: Array<RelationTypeResponseModel & { type: 'relation-type' }>
 		parentObjectTypeName: 'Document',
 		childObjectTypeName: 'Document',
 		type: 'relation-type',
+		parentKey: null,
 	},
 	{
 		key: 'ac68cde6-763f-4231-a751-1101b57defd2',
@@ -31,6 +32,7 @@ export const data: Array<RelationTypeResponseModel & { type: 'relation-type' }>
 		parentObjectTypeName: 'Document',
 		childObjectTypeName: 'Document',
 		type: 'relation-type',
+		parentKey: null,
 	},
 	{
 		key: '6f9b800c-762c-42d4-85d9-bf40a77d689e',
@@ -45,6 +47,7 @@ export const data: Array<RelationTypeResponseModel & { type: 'relation-type' }>
 		parentObjectTypeName: 'Document',
 		childObjectTypeName: 'Document',
 		type: 'relation-type',
+		parentKey: null,
 	},
 	{
 		key: 'd421727d-43de-4205-b4c6-037404f309ad',
@@ -59,6 +62,7 @@ export const data: Array<RelationTypeResponseModel & { type: 'relation-type' }>
 		parentObjectTypeName: 'Document',
 		childObjectTypeName: 'Document',
 		type: 'relation-type',
+		parentKey: null,
 	},
 	{
 		key: 'e9a0a28e-2d5b-4229-ac00-66f2df230513',
@@ -73,6 +77,7 @@ export const data: Array<RelationTypeResponseModel & { type: 'relation-type' }>
 		parentObjectTypeName: 'Document',
 		childObjectTypeName: 'Document',
 		type: 'relation-type',
+		parentKey: null,
 	},
 ];