Lyo.Validation 1.0.0

Lyo.Validation

Lyo.Validation contains reusable C# validators, fluent rule builders, validation attributes, and adapters that return structured Lyo.Result.Result<T> failures. Errors are populated through Lyo.Result.Error so callers can render Problem Details, log structurally, or aggregate into BulkResult.

Examples

Typical usage

using Lyo.Validation;

var validator = ValidatorBuilder<CreateUserRequest>.Create()
    .RuleFor(x => x.Name)
    .NotWhiteSpace()
    .Length(2, 50)
    .RuleFor(x => x.Email)
    .Email()
    .RuleFor(x => x.Age)
    .InclusiveBetween(18, 120)
    .Build();

var result = validator.Validate(new CreateUserRequest { Name = "Matt", Email = "matt@example.com", Age = 33 });

Attribute-based validation

public sealed class CreateUserRequest {
    [NotWhiteSpace]
    [Length(2, 50)]
    public string Name { get; init; } = string.Empty;

    [Email]
    public string Email { get; init; } = string.Empty;

    [Range(18, 120)]
    public int Age { get; init; }
}

Result<CreateUserRequest> result = new CreateUserRequest { /* ... */ }.ValidateWithAttributes();

What lives here

• Fluent validator composition via ValidatorBuilder<T> and PropertyValidatorBuilder<T, TProperty>.
• Attribute-based validation through built-in attributes such as Required, NotEmpty, NotWhiteSpace, Length, Regex, Email, Phone, Uri, and Range (in Lyo.Validation.Attributes).
• AttributeValidator<T> for reflection-driven validation across both Lyo's ValidationAttributeBase and System.ComponentModel.DataAnnotations (including IValidatableObject).
• Structured property metadata via ValidationMetadataKeys (PropertyName, AttemptedValue) attached to each failing Error.Metadata.
• Stable error codes via Lyo.Result.ValidationErrorCodes (e.g. NullValue, EmptyValue, InvalidLength, InvalidEmail, OutOfRange, ValidationFailed).

Attribute-based validation

AttributeValidator<T> reads validation attributes from T's public, instance-readable properties (compiled property getters are cached statically per T). It composes Lyo's own ValidationAttributeBase attributes with System.ComponentModel.DataAnnotations.ValidationAttribute, and — when T implements IValidatableObject — also runs Validate(ValidationContext). AttributeValidator<T>.Shared exposes a cached singleton; convenience extension value.ValidateWithAttributes() calls it.

DataAnnotations error codes are mapped onto Lyo.Result.ValidationErrorCodes (e.g. RequiredAttribute → RequiredValue, EmailAddressAttribute → InvalidEmail, RangeAttribute → OutOfRange); anything not mapped falls back to ValidationFailed.

Dependencies

Generated from ProjectReference / PackageReference (same model as docs/Lyo.ProjectGraph.html).

• Lyo.Common — (direct, lyo)
• Lyo.Exceptions — (direct, lyo)
• Lyo.Result — (direct, lyo)
• System.ComponentModel.Annotations 5.0.0 — (direct, microsoft)
• Microsoft.Extensions.Logging.Abstractions 10.0.5 — (transitive, microsoft)
• System.Memory 4.6.3 — (transitive, microsoft, netstandard2.0)
• System.Text.Json 10.0.5 — (transitive, microsoft, netstandard2.0)