Comandos

Inicio Rápido

#[derive(Entity)]
#[entity(table = "users", commands)]
#[command(Register)]
#[command(UpdateEmail: email)]
#[command(Deactivate, requires_id)]
pub struct User {
 #[id]
 pub id: Uuid,
 #[field(create, update, response)]
 pub email: String,
 #[field(create, response)]
 pub name: String,
 #[field(response)]
 pub active: bool,
}

Código Generado

Estructuras de Comando

/// Payload de comando para operación Register en User.
#[derive(Debug, Clone)]
pub struct RegisterUser {
 pub email: String,
 pub name: String,
}
/// Payload de comando para operación UpdateEmail en User.
#[derive(Debug, Clone)]
pub struct UpdateEmailUser {
 pub id: Uuid,
 pub email: String,
}
/// Payload de comando para operación Deactivate en User.
#[derive(Debug, Clone)]
pub struct DeactivateUser {
 pub id: Uuid,
}

Enum de Comando

/// Enum de comando para entidad User.
#[derive(Debug, Clone)]
pub enum UserCommand {
 Register(RegisterUser),
 UpdateEmail(UpdateEmailUser),
 Deactivate(DeactivateUser),
}
impl EntityCommand for UserCommand {
 fn kind(&self) -> CommandKind {
 match self {
 UserCommand::Register(_) => CommandKind::Create,
 UserCommand::UpdateEmail(_) => CommandKind::Update,
 UserCommand::Deactivate(_) => CommandKind::Custom,
 }
 }
 fn name(&self) -> &'static str {
 match self {
 UserCommand::Register(_) => "Register",
 UserCommand::UpdateEmail(_) => "UpdateEmail",
 UserCommand::Deactivate(_) => "Deactivate",
 }
 }
}

Enum de Resultado

/// Enum de resultado para ejecución de comando User.
#[derive(Debug, Clone)]
pub enum UserCommandResult {
 Register(User),
 UpdateEmail(User),
 Deactivate,
}

Trait de Handler

/// Trait async para manejar comandos User.
#[async_trait]
pub trait UserCommandHandler: Send + Sync {
 type Error: std::error::Error + Send + Sync;
 type Context: Send + Sync;
 /// Despachar comando al handler apropiado.
 async fn handle(&self, cmd: UserCommand, ctx: &Self::Context)
 -> Result<UserCommandResult, Self::Error>;
 /// Manejar comando Register.
 async fn handle_register(&self, cmd: RegisterUser, ctx: &Self::Context)
 -> Result<User, Self::Error>;
 /// Manejar comando UpdateEmail.
 async fn handle_update_email(&self, cmd: UpdateEmailUser, ctx: &Self::Context)
 -> Result<User, Self::Error>;
 /// Manejar comando Deactivate.
 async fn handle_deactivate(&self, cmd: DeactivateUser, ctx: &Self::Context)
 -> Result<(), Self::Error>;
}

Referencia de Sintaxis de Comandos

Comando Básico

#[command(Register)]
// Generado: RegisterUser { email, name }

Campos Específicos

#[command(UpdateEmail: email)]
// Generado: UpdateEmailUser { id, email }
#[command(UpdateProfile: name, bio, avatar)]
// Generado: UpdateProfileUser { id, name, bio, avatar }

Operación de Dominio

#[command(VerifyPassport, payload(passport_provider), sets(
 passport_verified = "true",
 passport_verified_at = "NOW()"
))]
// Genera: VerifyPassportUser { id, passport_provider }
// pool.verify_passport(command) -> User

let mut tx = pool.begin().await?;
let verified = UserTransactionRepo::new(&mut tx)
 .verify_passport(VerifyPassportUser { id, passport_provider: Some("gov".into()) })
 .await?;
tx.commit().await?;

Comando Solo ID

#[command(Deactivate, requires_id)]
// Generado: DeactivateUser { id }
#[command(Delete, requires_id, kind = "delete")]
// Generado: DeleteUser { id }, devuelve ()

Payload Personalizado

pub struct TransferPayload {
 pub from_account: Uuid,
 pub to_account: Uuid,
 pub amount: i64,
}
#[command(Transfer, payload = "TransferPayload")]
// Usa TransferPayload directamente

Resultado Personalizado

pub struct TransferResult {
 pub transaction_id: Uuid,
 pub success: bool,
}
#[command(Transfer, payload = "TransferPayload", result = "TransferResult")]
// Devuelve TransferResult en lugar de entidad

Opciones de Source

#[command(Create, source = "create")] // Usa campos #[field(create)] (defecto)
#[command(Modify, source = "update")] // Usa campos #[field(update)] (opcional)
#[command(Ping, source = "none")] // Sin campos de payload

Hints de Kind

#[command(Create, kind = "create")] // Devuelve entidad (defecto)
#[command(Update, kind = "update")] // Devuelve entidad
#[command(Remove, kind = "delete")] // Devuelve ()
#[command(Process, kind = "custom")] // Inferido de source

Ejemplo de Implementación

use async_trait::async_trait;
struct UserHandler {
 pool: PgPool,
 email_service: EmailService,
}
struct RequestContext {
 user_id: Option<Uuid>,
 correlation_id: Uuid,
}
#[async_trait]
impl UserCommandHandler for UserHandler {
 type Error = AppError;
 type Context = RequestContext;
 async fn handle(&self, cmd: UserCommand, ctx: &Self::Context)
 -> Result<UserCommandResult, Self::Error>
 {
 match cmd {
 UserCommand::Register(c) => {
 let user = self.handle_register(c, ctx).await?;
 Ok(UserCommandResult::Register(user))
 }
 UserCommand::UpdateEmail(c) => {
 let user = self.handle_update_email(c, ctx).await?;
 Ok(UserCommandResult::UpdateEmail(user))
 }
 UserCommand::Deactivate(c) => {
 self.handle_deactivate(c, ctx).await?;
 Ok(UserCommandResult::Deactivate)
 }
 }
 }
 async fn handle_register(&self, cmd: RegisterUser, ctx: &Self::Context)
 -> Result<User, Self::Error>
 {
 // Validar
 if cmd.email.is_empty() {
 return Err(AppError::Validation("Email requerido".into()));
 }
 // Crear usuario
 let user = User {
 id: Uuid::now_v7(),
 email: cmd.email.to_lowercase(),
 name: cmd.name,
 active: true,
 };
 // Persistir
 sqlx::query(
 "INSERT INTO users (id, email, name, active) VALUES (1,ドル 2,ドル 3,ドル 4ドル)"
 )
 .bind(user.id)
 .bind(&user.email)
 .bind(&user.name)
 .bind(user.active)
 .execute(&self.pool)
 .await?;
 // Efectos secundarios
 self.email_service.send_welcome(&user.email).await?;
 Ok(user)
 }
 async fn handle_update_email(&self, cmd: UpdateEmailUser, ctx: &Self::Context)
 -> Result<User, Self::Error>
 {
 // Verificar autorización
 if ctx.user_id != Some(cmd.id) {
 return Err(AppError::Forbidden("No puede actualizar email de otro usuario".into()));
 }
 // Actualizar
 let user: User = sqlx::query_as(
 "UPDATE users SET email = 1ドル WHERE id = 2ドル RETURNING *"
 )
 .bind(&cmd.email.to_lowercase())
 .bind(cmd.id)
 .fetch_one(&self.pool)
 .await?;
 // Enviar verificación
 self.email_service.send_verification(&user.email).await?;
 Ok(user)
 }
 async fn handle_deactivate(&self, cmd: DeactivateUser, ctx: &Self::Context)
 -> Result<(), Self::Error>
 {
 sqlx::query("UPDATE users SET active = false WHERE id = 1ドル")
 .bind(cmd.id)
 .execute(&self.pool)
 .await?;
 Ok(())
 }
}

Usando Comandos

async fn register_user(
 handler: &impl UserCommandHandler,
 email: String,
 name: String,
) -> Result<User, AppError> {
 let cmd = RegisterUser { email, name };
 let ctx = RequestContext {
 user_id: None,
 correlation_id: Uuid::new_v4(),
 };
 match handler.handle(UserCommand::Register(cmd), &ctx).await? {
 UserCommandResult::Register(user) => Ok(user),
 _ => unreachable!(),
 }
}
// O llamar handler específico directamente
async fn update_email(
 handler: &impl UserCommandHandler,
 user_id: Uuid,
 new_email: String,
 ctx: &RequestContext,
) -> Result<User, AppError> {
 let cmd = UpdateEmailUser {
 id: user_id,
 email: new_email,
 };
 handler.handle_update_email(cmd, ctx).await
}

Trait EntityCommand

use entity_derive::{EntityCommand, CommandKind};
let cmd = UserCommand::Register(register_data);
// Obtener metadatos del comando
assert_eq!(cmd.name(), "Register");
assert!(matches!(cmd.kind(), CommandKind::Create));
// Pattern matching
match cmd.kind() {
 CommandKind::Create => println!("Creando entidad"),
 CommandKind::Update => println!("Actualizando entidad"),
 CommandKind::Delete => println!("Eliminando entidad"),
 CommandKind::Custom => println!("Operación personalizada"),
}

Hooks de Comandos

#[derive(Entity)]
#[entity(table = "orders", commands, hooks)]
#[command(Place)]
#[command(Cancel, requires_id)]
pub struct Order { /* ... */ }

#[async_trait]
pub trait OrderHooks: Send + Sync {
 type Error: std::error::Error + Send + Sync;
 // Hooks CRUD estándar...
 // Hooks específicos de comandos
 async fn before_command(&self, cmd: &OrderCommand) -> Result<(), Self::Error>;
 async fn after_command(&self, cmd: &OrderCommand, result: &OrderCommandResult) -> Result<(), Self::Error>;
}

Mejores Prácticas

Patrón CQRS

#[derive(Entity)]
#[entity(table = "orders", commands)]
#[projection(Summary: id, status, total_cents, created_at)]
#[projection(Details: id, status, items, shipping_address, total_cents)]
#[command(Place)]
#[command(Ship, requires_id)]
#[command(Cancel, requires_id)]
pub struct Order { /* ... */ }
// Comandos (lado de escritura)
let result = handler.handle(OrderCommand::Place(place_order), &ctx).await?;
// Consultas (lado de lectura)
let summary = repo.find_by_id_summary(order_id).await?;
let details = repo.find_by_id_details(order_id).await?;

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