public ProductsListViewModel(ProductsSearchViewModel productsSearchViewModel, ProductAddEditViewModel productAddEditViewModel, ICategoryService categoryService, ISuppliersService suppliersService) : base(productsSearchViewModel, productAddEditViewModel) { ListingIncludes = new Expression <Func <Product, object> >[] { p => p.Category, p => p.Supplier }; PreAddEditDelegate = (type) => { productAddEditViewModel.Categories = categoryService.GetALL(); productAddEditViewModel.Suppliers = suppliersService.GetALL(); }; }