流畅的验证添加带有索引的规则

Question

我为这个模型做了一个流畅的验证类

 public class OnlineCashierRequest
 {
    Guid InvoiceId { get; set; }      
    string ClientPhoneOrEmail { get; set; }    
    List<IOnlineCashierProduct> Products { get; set; }
 }

public interface IOnlineCashierProduct
{
     string Name { get; set; }
     decimal Amount { get; set; }
     int Count { get; set; }
}

我对

products

有一个规则，其中金额等于空。但是我如何在消息行索引中写入

$"Amount is less zero for row {rowIndex}"

RuleForEach(t => t.Products)
    .Must(x => x.Amount < 0)
    .WithMessage(x => $"[{rowIndex}] Amount must be greater then zero\r\n");

Answer 1

https://docs.fluidation.net/en/latest/collections.html

RuleForEach(t => t.Products)
    .Must(x => x.Amount < 0)
    .WithMessage(x => $"[{CollectionIndex}] Amount must be greater than zero\r\n");

Answer 2

如果您只需要错误消息中的索引，Simon H 的答案就可以完成任务。

我不建议任何人这样做，但您始终可以让 FluentValidation 为您验证其他所有内容，然后在覆盖

Validate

方法中自行添加自定义错误。您可以使用验证上下文中所需的任何内容，并完全控制生成的任何错误

using FluentValidation;
using FluentValidation.Results;

public class NeedsValidating
{
    public List<string> StringCollection { get; set; } = new List<string>();
    public int OtherNumber { get; set; }
    public List<string> OtherStringCollection { get; set; } = new List<string>();
}

public class IndexValidator : AbstractValidator<NeedsValidating>
{
    /// <remarks>
    /// The usual Fluent Validation good stuff goes in the constructor
    /// </remarks>
    public IndexValidator()
    {
        RuleFor(nv => nv.OtherStringCollection).NotEmpty().WithMessage("Whatever");
    }

    /// <remarks>
    /// Depending on your use case, you may have to remove errors as well
    /// </remarks>
    public override ValidationResult Validate(ValidationContext<NeedsValidating> context)
    {
        var strings = context.InstanceToValidate.StringCollection;
        var result = base.Validate(context);
        for (int index = 0; index < strings.Count(); index++)
        {
            if (!IsValid(strings, index))
            {
                result.Errors.Add(new ValidationFailure("Custom Property with index", "Custom Message with index", strings[index]));
            }
        }
        // keep going, validate other stuff here if you want to

        return result;
    }

    private bool IsValid(List<string> strings, int index) => false; // throw new NotImplementedException("Whatever you want");

}

显然，这意味着在完全控制的情况下，您必须编写验证库通常为您执行的样板代码，并且旨在避免这种情况。像这样编写验证并使用 FluentValidation 并没有什么意义，除非您只想真正自定义一些东西

使用示例：

using Xunit;
using FluentAssertions;

    [Fact]
    public void TestTheValidator()
    {
        var input = new NeedsValidating
        {
             StringCollection = new List<string>{ "Whatever 1", "Whatever 2", "Whatever 3" }
        };

        var result = new IndexValidator().Validate(input);

        result.IsValid.Should().BeFalse();
        result.Errors.Should().HaveCount(4);
        result.Errors.Where(e => e.ErrorMessage == "Whatever").Should().HaveCount(1);
        result.Errors.Where(e => e.ErrorMessage == "Custom Message with index").Should().HaveCount(3);
    }