NGRX Effect and withLatestFrom example

item.effects.ts

    @Effect()
    selectItem$ = this.actions$.pipe(
        ofType(itemAction.ITEM_SELECT),
        concatMap(() =>
            this.store.select(fromItems.getItemsSelected)
        ),
        withLatestFrom(
            this.store.select(fromUi.getItemsSideviewVisible)
        ),
        filter(
            // Do not dispatch new action if sideview is already visible
            ([selected, sideViewVisible]) =>
                !sideViewVisible && selected.length > 0
        ),
        map(() => new uiAction.ShowItemsSideview())
    );