10.90-源码系列 - 10.90.02-Volo.Abp.Validation - 《.Net Core 学习笔记》

MvcFilter
拦截器
- 源码地址">流程源码地址

MvcFilter

在Volo.Abp.AspNetCore.Mvc 👉 Validation文件夹中

namespace Volo.Abp.AspNetCore.Mvc.Validation;
public class AbpValidationActionFilter : IAsyncActionFilter, ITransientDependency
{
    public async Task OnActionExecutionAsync(ActionExecutingContext context, ActionExecutionDelegate next)
    {
        // 是否是控制器行为
        // 是否是JsonResult、ObjectResult、NoContentResultd的一种
        // 不是则跳过
        if (!context.ActionDescriptor.IsControllerAction() ||
            !context.ActionDescriptor.HasObjectResult())
        {
            await next();
            return;
        }
        // 是否开启验证
        if (!context.GetRequiredService<IOptions<AbpAspNetCoreMvcOptions>>().Value.AutoModelValidation)
        {
            await next();
            return;
        }
        // 该方法是否禁用验证
        if (ReflectionHelper.GetSingleAttributeOfMemberOrDeclaringTypeOrDefault<DisableValidationAttribute>(context.ActionDescriptor.GetMethodInfo()) != null)
        {
            await next();
            return;
        }
        // 该控制器是否禁用验证
        if (ReflectionHelper.GetSingleAttributeOfMemberOrDeclaringTypeOrDefault<DisableValidationAttribute>(context.Controller.GetType()) != null)
        {
            await next();
            return;
        }
        // https://docs.microsoft.com/zh-cn/dotnet/api/system.reflection.memberinfo.declaringtype
        // 该方法的声明是不是上下文中控制器的
        if (context.ActionDescriptor.GetMethodInfo().DeclaringType != context.Controller.GetType())
        {
            var baseMethod = context.ActionDescriptor.GetMethodInfo();
            // 获取重写前的方法
            var overrideMethod = context.Controller.GetType().GetMethods().FirstOrDefault(x =>
                x.DeclaringType == context.Controller.GetType() &&
                x.Name == baseMethod.Name &&
                x.ReturnType == baseMethod.ReturnType &&
                x.GetParameters().Select(p => p.ToString()).SequenceEqual(baseMethod.GetParameters().Select(p => p.ToString())));
            if (overrideMethod != null)
            {
                // 该方法是否禁用验证
                if (ReflectionHelper.GetSingleAttributeOfMemberOrDeclaringTypeOrDefault<DisableValidationAttribute>(overrideMethod) != null)
                {
                    await next();
                    return;
                }
            }
        }
        // 调用IModelStateValidator模型状态验证器进行验证
        context.GetRequiredService<IModelStateValidator>().Validate(context.ModelState);
        await next();
    }
}

IModelStateValidator的默认实现ModelStateValidator。实现很简单，就是判断是否通过验证，然后将未通过的验证提示信息，添加到验证结果中，然后用验证异常AbpValidationException抛出，交给异常处理器处理。

namespace Volo.Abp.AspNetCore.Mvc.Validation;
public class ModelStateValidator : IModelStateValidator, ITransientDependency
{
    public virtual void Validate(ModelStateDictionary modelState)
    {
        var validationResult = new AbpValidationResult();
        AddErrors(validationResult, modelState);
        if (validationResult.Errors.Any())
        {
            throw new AbpValidationException(
                "ModelState is not valid! See ValidationErrors for details.",
                validationResult.Errors
            );
        }
    }
    public virtual void AddErrors(IAbpValidationResult validationResult, ModelStateDictionary modelState)
    {
        if (modelState.IsValid)
        {
            return;
        }
        foreach (var state in modelState)
        {
            foreach (var error in state.Value.Errors)
            {
                validationResult.Errors.Add(new ValidationResult(error.ErrorMessage, new[] { state.Key }));
            }
        }
    }
}

通过AbpMvcOptionsExtensions扩展方法统一将过滤器注入到Mvc过滤器集合中。

internal static class AbpMvcOptionsExtensions
{
    public static void AddAbp(this MvcOptions options, IServiceCollection services)
    {
        ,..
        // 注入
        AddActionFilters(options);
        ...
    }
    private static void AddActionFilters(MvcOptions options)
    {
        ...
        // 验证过滤器
        options.Filters.AddService(typeof(AbpValidationActionFilter));
        ...
    }
    ...
}

拦截器

只要实现了IValidationEnabled接口就将其添加到拦截器中。

public static class ValidationInterceptorRegistrar
{
    public static void RegisterIfNeeded(IOnServiceRegistredContext context)
    {
        if (ShouldIntercept(context.ImplementationType))
        {
            context.Interceptors.TryAdd<ValidationInterceptor>();
        }
    }
    private static bool ShouldIntercept(Type type)
    {
        return !DynamicProxyIgnoreTypes.Contains(type) && typeof(IValidationEnabled).IsAssignableFrom(type);
    }
}

流程源码地址

拦截器组装MethodInvocationValidationContext上下文，调用IMethodInvocationValidator.ValidateAsync进行验证。
默认实现MethodInvocationValidator，先进行判断
1. 参数不能为空
2. 修饰符必须是Public
3. 未使用DisableValidationAttribute特性
4. 参数数量和参数值数量相等(一对一)
MethodInvocationValidator调用IObjectValidator.GetErrorsAsync()方法获取验证结果
默认实现ObjectValidator调用AbpValidationOptions选项中的ObjectValidationContributors属性，该属性提供了IObjectValidationContributor集合，IObjectValidationContributor是验证辅助类型。当前类库中提供了DataAnnotationObjectValidationContributor模型注解验证，就是上面MVC那一套。
1. DataAnnotationObjectValidationContributor里面使用了递归验证，最大深度为8。
DataAnnotationObjectValidationContributor调用了DefaultAttributeValidationResultProvider获取验证结果，默认实现使用了ValidationAttribute.GetValidationResult()
1. 在MVC中重新用AbpMvcAttributeValidationResultProvider继承并重写了DefaultAttributeValidationResultProvider的GetOrDefault()方法。用它实现了本地化。 ```csharp namespace Volo.Abp.AspNetCore.Mvc.Localization;

[Dependency(ReplaceServices = true)] public class AbpMvcAttributeValidationResultProvider : DefaultAttributeValidationResultProvider { private readonly AbpMvcDataAnnotationsLocalizationOptions _abpMvcDataAnnotationsLocalizationOptions; private readonly IStringLocalizerFactory _stringLocalizerFactory;

public AbpMvcAttributeValidationResultProvider(
    IOptions<AbpMvcDataAnnotationsLocalizationOptions> abpMvcDataAnnotationsLocalizationOptions,
    IStringLocalizerFactory stringLocalizerFactory)
{
    _abpMvcDataAnnotationsLocalizationOptions = abpMvcDataAnnotationsLocalizationOptions.Value;
    _stringLocalizerFactory = stringLocalizerFactory;
}
public override ValidationResult GetOrDefault(ValidationAttribute validationAttribute, object validatingObject, ValidationContext validationContext)
{
    var resourceSource = _abpMvcDataAnnotationsLocalizationOptions.AssemblyResources.GetOrDefault(validationContext.ObjectType.Assembly);
    if (resourceSource == null)
    {
        return base.GetOrDefault(validationAttribute, validatingObject, validationContext);
    }
    if (validationAttribute.ErrorMessage == null)
    {
        ValidationAttributeHelper.SetDefaultErrorMessage(validationAttribute);
    }
    if (validationAttribute.ErrorMessage != null)
    {
        validationAttribute.ErrorMessage = _stringLocalizerFactory.Create(resourceSource)[validationAttribute.ErrorMessage];
    }
    return base.GetOrDefault(validationAttribute, validatingObject, validationContext);
}

}

<a name="d0tco"></a>
## FluentValidation
引入了第三方类库`FluentValidation`，并实现了`IObjectValidationContributor`。
```csharp
namespace Volo.Abp.FluentValidation;
public class FluentObjectValidationContributor : IObjectValidationContributor, ITransientDependency
{
    private readonly IServiceProvider _serviceProvider;
    public FluentObjectValidationContributor(
        IServiceProvider serviceProvider)
    {
        _serviceProvider = serviceProvider;
    }
    // 通过Ioc获取验证器，然后将验证结果添加到上下文的Errors集合中。
    public virtual async Task AddErrorsAsync(ObjectValidationContext context)
    {
        var serviceType = typeof(IValidator<>).MakeGenericType(context.ValidatingObject.GetType());
        var validator = _serviceProvider.GetService(serviceType) as IValidator;
        if (validator == null)
        {
            return;
        }
        // 获取验证结果
        var result = await validator.ValidateAsync((IValidationContext)Activator.CreateInstance(
            typeof(ValidationContext<>).MakeGenericType(context.ValidatingObject.GetType()),
            context.ValidatingObject));
        if (!result.IsValid)
        {
            // 返回验证失败信息
            context.Errors.AddRange(
                result.Errors.Select(
                    error =>
                        new ValidationResult(error.ErrorMessage, new[] { error.PropertyName })
                )
            );
        }
    }
}

10.90.02-Volo.Abp.Validation

MvcFilter

拦截器

流程 源码地址

流程源码地址