shesha-fluent-validators

name

shesha-fluent-validators

description

Creates FluentValidation validators for Shesha entity CRUD endpoints. Generates validator classes, module IoC registration, and custom app service integration. Covers conditional validation rules, auto-population of related properties, and cross-property business logic. Use when the user asks to add validation, business rules, conditional required fields, auto-populate properties, or enforce constraints on entity create or update. Also use when the user wants to add logic that runs automatically on CRUD endpoints without modifying the entity or creating a custom app service. Trigger phrases include "validate", "required when", "auto-populate", "auto-fill", "set automatically", "conditional required", "business rule on save", "enforce constraint".

Shesha FluentValidation Validators

Generate FluentValidation validators for Shesha entity CRUD endpoints based on $ARGUMENTS.

Instructions

• Inspect the target entity to determine its properties, relationships, and namespace.
• Inspect the Domain module class to check if validator IoC registration already exists.
• Validators go in the Domain layer alongside the entity they validate.
• CRITICAL: Module IoC registration is required — see §2 in reference/validator-artifacts.md.
• All validators must implement both AbstractValidator<TEntity> and ITransientDependency.
• For custom app services that bypass DynamicCrudAppService, inject IValidator<TEntity> and call it manually — see §3.

Artifact catalog

#	Artifact	Layer	Template
1	Validator Class	Domain	reference/validator-artifacts.md §1
2	Module IoC Registration	Domain	reference/validator-artifacts.md §2
3	Custom AppService Integration	Application	reference/validator-artifacts.md §3

Folder structure

{ModuleName}.Domain/
  Domain/{EntityNamePlural}/
    {EntityName}.cs              # existing entity
    {EntityName}Validator.cs     # NEW — validator class
  {ModuleName}Module.cs          # MODIFY — add IoC registration

{ModuleName}.Application/        # only if custom app service exists
  Services/{EntityNamePlural}/
    {EntityName}AppService.cs    # MODIFY — inject and call validator

How it works

Shesha's DynamicCrudAppService calls FluentValidationsOnEntityAsync<TEntity>() during both create and update. This method:

1. Checks StaticContext.IocManager.IsRegistered(typeof(IValidator<TEntity>))
2. If registered, resolves all IValidator<TEntity> implementations
3. Calls ValidateAsync() on each and maps errors to AbpValidationException

If the validator is not registered correctly, validation is silently skipped.

Critical: IoC registration gotchas

There are three requirements that must all be met for validators to work:

1. Implement ITransientDependency

public class MyValidator : AbstractValidator<MyEntity>, ITransientDependency

This alone is NOT sufficient — ABP registers the class by Self + DefaultInterfaces, which does NOT include IValidator<T>.

2. Register BEFORE RegisterAssemblyByConvention

Castle Windsor uses "first registration wins". If RegisterAssemblyByConvention runs first, it registers the validator class by Self only. Subsequent attempts to register it with IValidator<T> are silently ignored.

// CORRECT — validators registered first with IValidator<T> interface
IocManager.IocContainer.Register(
    Classes.FromAssembly(thisAssembly)
        .BasedOn(typeof(IValidator<>))
        .WithServiceAllInterfaces()
        .LifestyleTransient()
);
IocManager.RegisterAssemblyByConvention(thisAssembly);

// WRONG — RegisterAssemblyByConvention wins, IValidator<T> never registered
IocManager.RegisterAssemblyByConvention(thisAssembly);
IocManager.IocContainer.Register(
    Classes.FromAssembly(thisAssembly)
        .BasedOn(typeof(IValidator<>))
        .WithServiceAllInterfaces()  // silently ignored!
        .LifestyleTransient()
);

3. Use WithServiceAllInterfaces() not WithServiceBase()

• WithServiceBase() registers as AbstractValidator<T> (the base class) — framework cannot find it
• WithServiceAllInterfaces() registers as IValidator<T> (the interface) — framework resolves this

4. Custom app services need manual invocation

Custom app services that use _repository.InsertAsync() directly bypass the DynamicCrudAppService validation pipeline. You must inject IValidator<TEntity> and call ValidateAsync() manually.

Quick reference — common rule patterns

Pattern	Code	Use Case
Required field	RuleFor(x => x.Name).NotEmpty()	Always required
Conditional required	RuleFor(x => x.Province).NotNull().When(x => x.Role == Role.Head)	Required based on another field
Auto-populate	RuleFor(x => x.Prop).Custom((v, ctx) => { ctx.InstanceToValidate.Other = ...; })	Set derived values on save
Max length	RuleFor(x => x.Name).MaximumLength(100)	String constraints
Must match	RuleFor(x => x.Email).EmailAddress()	Format validation
Custom error	.WithMessage("Province is required for Provincial Head.")	User-friendly messages
Cross-property	RuleFor(x => x.EndDate).GreaterThan(x => x.StartDate)	Date/range validation
Unique check	RuleFor(x => x.Code).CustomAsync(async (v, ctx, ct) => { ... })	DB uniqueness (inject repository)

Checklist

Before generating, verify:

• Entity exists and you know its full namespace and properties
• Domain module class located (for IoC registration)
• Check if IoC registration already exists (avoid duplicates)
• Check if entity has custom app services that need manual validator calls
• Determine which properties need validation vs auto-population

Now generate the requested artifact(s) based on: $ARGUMENTS