SandwichOrder_BuildForm

SandwichOrder_BuildForm.cs

public static IForm<SandwichOrder> BuildForm()
{
    return new FormBuilder<SandwichOrder>()
        .Message("サンドイッチボットへようこそ♪")
        .Field(nameof(Toppings), 
                validate: async (state, value) =>
                {
                    var values = ((List<object>)value).OfType<ToppingOptions>();
                    var result = new ValidateResult() { IsValid = true, Value = values };
                    if (values != null && values.Contains(ToppingOptions.Everything))
                    {
                        result.Value = Enum.GetValues(typeof(ToppingOptions)).Cast<ToppingOptions>()
                                        .Where(t => t != ToppingOptions.Everything && !values.Contains(t)).ToList();
                    }
                    return result;
                })
                .Message("{Toppings}を選択しました。")
        .Build();
}