private _initDirective()

in libs/fabric/src/lib/components/command-bar/command-bar.component.ts [137:178]
33 lines of code
8 McCabe index (conditional complexity)

  private _initDirective<TCommandBarItemsDirective extends CommandBarItemsDirectiveBase>(
    directive: TCommandBarItemsDirective,
    itemsPropertyKey: 'items' | 'farItems' | 'overflowItems'
  ) {
    const transformItemsFunc =
      (directive instanceof CommandBarItemsDirective && (newItems => this._createTransformedItems(newItems))) ||
      (directive instanceof CommandBarFarItemsDirective && (newItems => this._createTransformedFarItems(newItems))) ||
      (directive instanceof CommandBarOverflowItemsDirective &&
        (newItems => this._createTransformedOverflowItems(newItems)));
    null;

    if (!transformItemsFunc) {
      throw new Error('Invalid directive given');
    }

    const setItems = (
      mapper: (items: ReadonlyArray<ICommandBarItemOptions>) => ReadonlyArray<ICommandBarItemOptions>
    ) => {
      this[itemsPropertyKey] = mapper(this[itemsPropertyKey]);
      transformItemsFunc(this[itemsPropertyKey]);

      this.markForCheck();
    };

    // Initial items
    setItems(() => directive.items);

    // Subscribe to adding/removing items
    this._subscriptions.push(
      directive.onItemsChanged.subscribe((newItems: QueryList<CommandBarItemDirective>) => {
        setItems(() => newItems.map<ICommandBarItemOptions>(directive => directive));
      })
    );

    // Subscribe for existing items changes
    this._subscriptions.push(
      directive.onChildItemChanged.subscribe(({ key, changes }: CommandBarItemChangedPayload) => {
        setItems(items => items.map(item => (item.key === key ? mergeItemChanges(item, changes) : item)));
        this.markForCheck();
      })
    );
  }