public async load()

in uui-core/src/data/processing/views/tree/treeState/TreeState.ts [49:98]
45 lines of code
13 McCabe index (conditional complexity)

    public async load<TFilter>({
        using,
        options,
        dataSourceState,
    }: LoadOptions<TItem, TId, TFilter>): Promise<TreeState<TItem, TId>> {
        const treeStructure = this.getTreeStructure(using);

        const { loadedItems, byParentId, nodeInfoById } = await FetchingHelper.load<TItem, TId, TFilter>({
            tree: treeStructure,
            options,
            dataSourceState,
        });

        if (!loadedItems.length && !byParentId.size && !nodeInfoById.size) {
            if (using === undefined && treeStructure !== this.getTreeStructure('visible')) {
                return this.withNewTreeStructures({
                    using,
                    treeStructure,
                    itemsMap: this.itemsMap,
                });
            }

            return this;
        }

        const itemsMap = loadedItems.length ? this.setItems(loadedItems, { on: 'load' }) : this.itemsMap;
        const newByParentId = byParentId.size ? cloneMap(treeStructure.byParentId) : treeStructure.byParentId;
        for (const [id, ids] of byParentId) {
            newByParentId.set(id, ids);
        }
        const newNodeInfoById = nodeInfoById.size ? cloneMap(treeStructure.nodeInfoById) : treeStructure.nodeInfoById;
        for (const [id, nodeInfo] of nodeInfoById) {
            newNodeInfoById.set(id, nodeInfo);
        }
        let treeToUpdate: TreeStructureId = using;
        if (treeToUpdate === 'visible') {
            treeToUpdate = dataSourceState.search ? 'visible' : undefined;
        }

        return this.withNewTreeStructures({
            using: treeToUpdate,
            treeStructure: TreeStructure.create(
                treeStructure.getParams(),
                ItemsAccessor.toItemsAccessor(itemsMap),
                newByParentId,
                newNodeInfoById,
            ),
            itemsMap,
        });
    }