CQRS + Event Sourcing in PHP. DDD Domain Driven Design

1. CQRS
Command Query Responsibility Segregation

2. Manel López Torrent
Ingeniero informática
Desarrollo software
Agile
@mloptor
malotor@gmail.com

4. EDUMENT
http://cqrs.nu
DDD in PHP
https://github.com/dddinphp/blog-cqrs
https://github.com/dddinphp/last-wishes-gamify

5. ¿CQRS?

6. CQRS
Patrón de diseño de app
Lecturas / Escrituras

7. Modelo rico
Mejor rendimiento
Mejor escalabilidad
Objetivos

8. Greg Young
https://goodenoughsoftware.net/
@gregyoung

9. DDD (Domain Driven Design)
Modelo rico VS Modelo Anémico
Patrones tácticos
Arquitectura de capas
Arquitectura hexagonal
Requisitos

10. Cafetería

11. - Cuandos los clientes entran en el café se sientan en una
mesa , un camarero/a , abre una cuenta para esa mesa
- Los clientes pueden ordenar bebida y/o comidas del
menú
- Una vez ordenadas las bebidas pueden ser servidas de
inmediato.
- La comida debe ser preparada en cocina. Una vez se ha
preparado puede ser servida
- Cuando los clientes terminan de comer pagan la cuenta (
pueden dejar propina ) y la cuenta se cierra
- No se puede cerrar una cuenta si hay bebida o comida
pendientes

12. Abrir
Ordenar
Preparar
Servir
Pagar
Cerrar
Camarero
Mesa
Cuenta
Bebida / Comida

14. Trasladar el modelo a objetos ( DDD táctico )
Creamos tests para asegurar su corrección
Arquitectura hexagonal para conectar el modelo con el mundo
exterior

15. Application Layer
Domain
Model
Application
Service 1
Request
Infrastructure
Layer DataStoreApplication
Service 2
Application
Service n
Response

16. <?php
class Tab
{
static public function open($table, $waiter): Tab {}
public function placeOrder($orderedItems) {}
public function serveDrinks($drinksServed) {}
public function prepareFood($foodPrepared) {}
public function serveFood($foodServed) {}
public function close(float $amount) {}
}
interface TabRepository
{
public function getById(TabId $tabId);
public function save(Tab $tab);
}

17. <?php
class OrderedItem
{
public function __construct(int $menuNumber, bool $IsDrink, float $price) {}
public function getMenuNumber(): int {}
public function isDrink(): bool {}
public function getPrice(): float {}
}
interface OrderedItemsRepository
{
public function findById($id): OrderedItem;
}

18. OK

19. Nuevos requisitos

20. Maître
Barman
Cocina

21. <?php
interface TabRepository
{
public function getById(TabId $tabId);
public function save(Tab $tab);
}

22. <?php
interface TabRepository
{
public function getById(TabId $tabId);
public function save(Tab $tab);
public function getTabsByWaiter($waiter);
public function getTabsWithDrinkPending();
public function getTabsWithFoodPrepared();
public function getTabsOpen();
public function getTabsClosed(DateTime $date);
}

23. <?php
use DoctrineORMQuery
interface TabRepository
{
public function getById(TabId $tabId);
public function save(Tab $tab);
public function getTabsByQuery(Query $query)
}

24. <?php
interface TabRepository
{
public function getById(TabId $tabId);
public function save(Tab $tab);
public function getTabsBySpeficication(Specification $s);
}

25. <?php
class MysqlTabRepository implements TabRepository { ... }
class RedisTabRepository implements TabRepository { ... }
class MongoDBTabRepository implements TabRepository { ... }
¿?

26. ORM
Frameworks

27. Contaminamos el modelo

28. SRP

29. SRP

30. Command Query
Responsibility
Segregation

31. Read Model Write Model

32. Read Model Write Model
Lógica de
negocio

33. Read Model Write Model
Query Command

34. Commands
OpenTab
PlaceOrder
MarkDrinksServed
MarkFoodPrepared
MarkFoodServed
CloseTab
Querys
AllTabs
OneTab
AllTabsByWaiter

35. Infrastructure
Layer
Application
Layer
Command
HandlerCommand
Command
Handler
Query
Handle
Read Model
Model
Command
Query
DataStore
Response
Query
Handle
Query
Response

36. Controladores Comando Bus Command Handler

37. Command
CommandHandler

38. class OpenTabCommand
{
private $tabId;
private $tableNumber;
private $waiterId;
public function __construct($tabId, $tableNumber, $waiterId)
{
$this->tabId = $tabId;
$this->tableNumber = $tableNumber;
$this->waiterId = $waiterId;
}
public function getTabId() { }
public function getTableNumber() { }
public function getWaiterId() { }
}

39. class OpenTabHandler
{
private $tabRepopsitory;
public function __construct(TabRepository $tabRepository)
{
$this->tabRepopsitory = $tabRepository;
}
public function handle(OpenTabCommand $command)
{
$newTab = Tab::openWithId(
TabId::fromString($command->getTabId()),
$command->getTableNumber(),
$command->getWaiterId()
);
$this->tabRepopsitory->add($newTab);
}
}

40. Query
QueryHandler

41. class OneTabQuery
{
public $id;
public function __construct($id)
{
$this->id = $id;
}
}

42. class OneTabQueryHandler
{
private $tabsRepository;
private $dataTransformer;
public function __construct(
TabsRepository $tabsRepostiory,
DataTranformer $dataTransformer
) {
$this->tabsRepository = $tabsRepostiory;
$this->dataTransformer = $dataTransformer;
}
public function handle(OneTabQuery $query)
{
$tab = $this->tabsRepository->find($query->id);
$this->dataTransformer->write($tab);
return $this->dataTransformer->read();
}
}

43. Modelo Escritura
Tab
TabRepository
OrderedItem
OrderedItemRepository
Modelo Lectura
TabView
TabViewRepository
OrderedItemView
OrderedItemViewRepository

44. Modelo Escritura
Tab
TabRepository
OrderedItem
OrderedItemRepository
Modelo Lectura
TabView
TabViewRepository
OrderedItemView
OrderedItemViewRepository
Lógica negocio
Modelo Anémico

45. <?php
interface TabRepository
{
public function getById(TabId $tabId);
public function save(Tab $tab);
}
interface TabViewRepository
{
public function getTabsByWaiter($waiter);
public function getTabsWithDrinkPending();
public function getTabsWithFoodPrepared();
public function getTabsOpen();
public function getTabsClosed(DateTime $date);
}

46. Modelo rico
Mejor rendimiento
Mejor escalabilidad

47. ¿Mejor rendimiento?

48. Infrastructure
Layer
Application
Layer
Command
HandlerCommand
Command
Handler
Query
Handle
Read Model
Model
Command
Query
DataStore
Response
Query
Handle
Query
Response

49. Model Infrastructure
Layer
DataStore
Infrastructure
Layer
DataStore
Application
Layer
Command
HandlerCommand
Command
Handler
Query
Handle
Read Model
Command
Query
Response
Query
Handle
Query
Response

50. <?php
class RedisTabRepository implements TabRepository { ... }
class MysqlTabViewRepository implements TabViewRepository { ... }

51. Modelo rico
Mejor rendimiento
Mejor escalabilidad

52. ¿Mejor escalabilidad?

53. Model Infrastructure
Layer
DataStore
Infrastructure
Layer
DataStore
Application
Layer
Command
HandlerCommand
Command
Handler
Query
Handle
Read Model
Command
Query
Response
Query
Handle
Query
Response
WRITE SERVICE
READ SERVICE

54. API
GATEWA
Y
READ
SERVICE
WRITE
SERVICE
READ
SERVICE
READ
SERVICE

55. Modelo rico
Mejor rendimiento
Mejor escalabilidad

56. ¿Consistencia de los datos?

57. Infrastructure
Layer
Application Layer
Command
HandlerCommand
Command
Handler
Query
Handle
Read Model
Model
Command
Query
DataStore
Response
Query
Handle
Query
Response
Infrastructure
Layer
DataStore

58. Eventos del dominio

59. Se ha abierto una cuenta
Se ordenan bebidas y comida
La comida está preparada
Las bebidas se han servido
La comida se ha preparado
La comida se ha servidor
Se ha cerrado una cuenta

60. TabOpened
DrinksOrdered
FoodOrdered
DrinksServed
FoodPrepared
FoodServed
TabClosed

61. <?php
class DrinksOrdered extends TabEvent
{
private $items;
public function __construct(TabId $id, $items)
{
$this->id = $id;
$this->items = $items;
}
public function getItems()
{
return $this->items;
}
}

62. Command Model

63. Evento
BUS
Model
Evento
Evento

64. Model Evento Listenner
BUS

65. DataStore
Model Listenner
BUS

66. Event sourcing

67. El estado de nuestro sistema
es la suma de todos los eventos
ocurridos en el.

68. A1 {
x = 1
y = 2
}
ID X Y
A1 1 2
A2 3 5 A2 {
x = 3
y = 5
}

69. A2, y = 5
A1, y = 2
A2, x = 3
A1 , y = 7
A2, x = null y = null
A1 , x = 1
A1, x = null y = null
A1 {
x = null
y = null
}
Tiempo

70. A2, y = 5
A1, y = 2
A2, x = 3
A1 , y = 7
A2, x = null y = null
A1 , x = 1
A1, x = null y = null
A1 {
x = null
y = null
}
A1 {
x = 1
y = null
}
Tiempo

71. A2, y = 5
A1, y = 2
A2, x = 3
A1 , y = 7
A2, x = null y = null
A1 , x = 1
A1, x = null y = null
A1 {
x = null
y = null
}
A1 {
x = 1
y = null
}
A2 {
x = null
y = null
}
Tiempo

72. A2, y = 5
A1, y = 2
A2, x = 3
A1 , y = 7
A2, x = null y = null
A1 , x = 1
A1, x = null y = null
A1 {
x = null
y = null
}
A1 {
x = 1
y = null
}
A1 {
x = 1
y = 7
}
A2 {
x = null
y = null
}
Tiempo

73. A2, y = 5
A1, y = 2
A2, x = 3
A1 , y = 7
A2, x = null y = null
A1 , x = 1
A1, x = null y = null
A1 {
x = null
y = null
}
A1 {
x = 1
y = null
}
A1 {
x = 1
y = 7
}
A2 {
x = null
y = null
}
A2 {
x = 3
y = null
}
Tiempo

74. A2, y = 5
A1, y = 2
A2, x = 3
A1 , y = 7
A2, x = null y = null
A1 , x = 1
A1, x = null y = null
A1 {
x = null
y = null
}
A1 {
x = 1
y = null
}
A1 {
x = 1
y = 7
}
A1 {
x = 1
y = 2
}
A2 {
x = null
y = null
}
A2 {
x = 3
y = null
}
Tiempo

75. A2, y = 5
A1, y = 2
A2, x = 3
A1 , y = 7
A2, x = null y = null
A1 , x = 1
A1, x = null y = null
A1 {
x = null
y = null
}
A1 {
x = 1
y = null
}
A1 {
x = 1
y = 7
}
A1 {
x = 1
y = 2
}
A2 {
x = null
y = null
}
A2 {
x = 3
y = null
}
A2 {
x = 3
y = 5
}
Tiempo

76. A2, y = 5
A1, y = 2
A2, x = 3
A1 , y = 7
A2, x = null y = null
A1 , x = 1
A1, x = null y = null
A1 {
x = null
y = null
}
A1 {
x = 1
y = null
}
A1 {
x = 1
y = 7
}
A1 {
x = 1
y = 2
}
A2 {
x = null
y = null
}
A2 {
x = 3
y = null
}
A2 {
x = 3
y = null
}

77. Historia
Auditoria
Fácil persistencia

78. Reconstruimos nuestros agregado a partir de un
flujo de eventos

79. Command Model

80. Evento
BUS
Model
Evento
Evento
EventStore

81. Proyecciones

82. ID X Y
A1 1 2
A2 3 5
A1, y = 2
A1 , y = 7
A1 , x = 1
A3, y = 5
A2, x = 3

83. ID X Y
A1 1 2
A2 3 5
A1, x = 2
A1, y = 2
A1 , y = 7
A1 , x = 1
A3, y = 5
A2, x = 3

84. ID X Y
A1 1 2
A2 3 5
UPDATE table_name
SET x=2 WHERE id =
A1A1, x = 2
A1, y = 2
A1 , y = 7
A1 , x = 1
A3, y = 5
A2, x = 3

85. ID X Y
A1 2 2
A2 3 5
A1, x = 2
A1, y = 2
A1 , y = 7
A1 , x = 1

86. Inconsistencia Eventual

87. ¿Dónde generamos los eventos?

88. Agregados

89. Entidad raíz
Id del agregado
Almacenar los eventos
Reconstruir desde flujo de eventos

90. <?php
class Tab
{
static public function open($table, $waiter): Tab {}
public function placeOrder($orderedItems) {}
public function serveDrinks($drinksServed) {}
public function prepareFood($foodPrepared) {}
public function serveFood($foodServed) {}
public function close(float $amount) {}
}

91. <?php
class Tab
{
// TabOpened
static public function open($table, $waiter): Tab {}
// DrinksOrdered , FoodOrdered
public function placeOrder($orderedItems) {}
// DrinksServed
public function serveDrinks($drinksServed) {}
// FoodPrepared
public function prepareFood($foodPrepared) {}
// FoodServed
public function serveFood($foodServed) {}
// TabClosed
public function close(float $amount) {}
}

92. <?php
class Tab {
static public function open($table, $waiter): Tab
{
$id = TabId::create();
$newTab = new Tab($id, $table, $waiter);
DomainEventPublisher::instance()->publish(
new TabOpened($id, $table, $waiter)
);
return $newTab;
}
}

93. <?php
class Tab {
static public function open($table, $waiter): Tab
{
$id = TabId::create();
$newTab = new Tab($id, $table, $waiter);
DomainEventPublisher::instance()->publish(
new TabOpened($id, $table, $waiter)
);
return $newTab;
}
}

94. <?php
class Tab extends Aggregate {
static public function open($table, $waiter): Tab
{
$id = TabId::create();
$newTab = new Tab($id, $table, $waiter);
$this->recordThat(new TabOpened($id, $table, $waiter));
return $newTab;
}
}

95. abstract class Aggregate implements AggregateRoot
{
private $recordedEvents = [];
protected function recordThat(DomainEvent $aDomainEvent)
{
$this->recordedEvents[] = $aDomainEvent;
}
public function getRecordedEvents(): DomainEvents
{
return new DomainEvents($this->recordedEvents);
}
public function clearRecordedEvents()
{
$this->recordedEvents = [];
}
}

96. abstract class Aggregate implements AggregateRoot
{
public static function reconstituteFrom(AggregateHistory $anAggregateHistory) {
$anAggregate = static::createEmptyWithId(
$anAggregateHistory->getAggregateId()
);
foreach ($anAggregateHistory as $anEvent) {
$anAggregate->apply($anEvent);
}
return $anAggregate;
}
private function apply($anEvent)
{
$method = 'apply' . ClassFunctions::short($anEvent);
$this->$method($anEvent);
}
}

97. class Tab extends Aggregate {
public function applyDrinksServed(DrinksServed $drinksServed)
{
array_walk($drinksServed->getItems(),
function($drinkServedNumber) {
$item = $this->outstandingDrinks[$drinkServedNumber];
unset($this->outstandingDrinks[$drinkServedNumber]);
$this->servedItems[$drinkServedNumber] = $item;
});
}
}

98. class Tab extends Aggregate {
public function applyDrinksServed(DrinksServed $drinksServed)
{
array_walk($drinksServed->getItems(),
function($drinkServedNumber) {
$item = $this->outstandingDrinks[$drinkServedNumber];
unset($this->outstandingDrinks[$drinkServedNumber]);
$this->servedItems[$drinkServedNumber] = $item;
});
}
}

99. Refactorizar agregados

100. <?php
class Tab {
public function serveDrinks($drinksServed)
{
$this->assertDrinksAreOutstanding($drinksServed);
array_walk($drinksServed, function($drinkServedNumber) {
$item = $this->outstandingDrinks[$drinkServedNumber];
unset($this->outstandingDrinks[$drinkServedNumber]);
$this->servedItems[$drinkServedNumber] = $item;
});
}
}

101. <?php
class Tab extends Aggregate {
public function serveDrinks($drinksServed)
{
$this->assertDrinksAreOutstanding($drinksServed);
array_walk($drinksServed, function($drinkServedNumber) {
$item = $this->outstandingDrinks[$drinkServedNumber];
unset($this->outstandingDrinks[$drinkServedNumber]);
$this->servedItems[$drinkServedNumber] = $item;
});
$this->recordThat(new DrinksServed(
$this->getAggregateId(),
$drinksServed
));
}
}

102. <?php
class Tab extends Aggregate {
public function applyDrinksServed(DrinksServed $drinksServed)
{
array_walk($drinksServed->getItems(),
function($drinkServedNumber) {
$item = $this->outstandingDrinks[$drinkServedNumber];
unset($this->outstandingDrinks[$drinkServedNumber]);
$this->servedItems[$drinkServedNumber] = $item;
});
}
}

103. <?php
class Tab extends Aggregate {
public function serveDrinks($drinksServed)
{
$this->assertDrinksAreOutstanding($drinksServed);
array_walk($drinksServed, function($drinkServedNumber) {
$item = $this->outstandingDrinks[$drinkServedNumber];
unset($this->outstandingDrinks[$drinkServedNumber]);
$this->servedItems[$drinkServedNumber] = $item;
});
$this->recordThat(new DrinksServed(
$this->getAggregateId(),
$drinksServed
));
}
}

104. <?php
class Tab extends Aggregate {
public function serveDrinks($drinksServed)
{
$this->assertDrinksAreOutstanding($drinksServed);
$drinksServedEvend = new DrinksServed(
$this->getAggregateId(),
$drinksServed
);
$this->recordThat($drinksServedEvend);
$this->apply($drinksServedEvend);
}
}

105. class Tab extends Aggregate {
public function serveDrinks($drinksServed)
{
$this->assertDrinksAreOutstanding($drinksServed);
$this->applyAndRecordThat(new DrinksServed(
$this->getAggregateId(),
$drinksServed
));
}
}

106. class Tab extends Aggregate {
public function serveDrinks($drinksServed)
{
$this->assertDrinksAreOutstanding($drinksServed);
$this->applyAndRecordThat(new DrinksServed(
$this->getAggregateId(),
$drinksServed
));
}
}
1 - Comprobamos que el evento se puede aplicar

107. class Tab extends Aggregate {
public function serveDrinks($drinksServed)
{
$this->assertDrinksAreOutstanding($drinksServed);
$this->applyAndRecordThat(new DrinksServed(
$this->getAggregateId(),
$drinksServed
));
}
}
1 - Comprobamos que el evento se puede aplicar
2 - Lo Aplicamos y lo guardamos

108. Repositorio

109. Recuperar flujo de eventos
Persistir eventos guardados
Publicar el flujo eventos

110. <?php
interface AggregateRepository
{
public function get(IdentifiesAggregate $aggregateId):
AggregateRoot;
public function add(RecordsEvents $aggregate);
}

111. <?php
class TabEventSourcingRepository implements TabRepository
{
private $eventStore;
private $projector;
public function __construct(
EventStore $eventStore,
$projector
) {
$this->eventStore = $eventStore;
$this->projector = $projector;
}
}

112. Event Store

113. <?php
interface EventStore
{
public function commit(DomainEvents $events);
public function getAggregateHistoryFor(IdentifiesAggregate $id);
}

114. Serializar

115. {
"type": "TabOpened",
"created_on": 1495579156,
"data": {
"id" : "8b486a7b-2e32-4e17-ad10-e90841286722",
"waiter" : "Jhon Doe",
"table" : 1
}
}
{
"type": "DrinksOrdered",
"created_on": 1495579200,
"data": {
"id" : "8b486a7b-2e32-4e17-ad10-e90841286722",
"items" : [1,2]
}
}
8b486a7b-2e32-4e17-ad10-e90841286722

116. Proyecciones

117. <?php
interface Projection
{
public function eventType();
public function project($event);
}

118. <?php
class TabOpenedProjection implements Projection
{
private $pdo;
public function __construct($pdo)
{
$this->pdo = $pdo;
}
public function project($event)
{
$stmt = $this->pdo->prepare("INSERT INTO tabs (tab_id, waiter, tableNumber, open) VALUES
(:tab_id, :waiter, :tableNumber, 1)");
$stmt->execute([
':tab_id' => $event->getAggregateId(),
':waiter' => $event->getWaiterId(),
':tableNumber' => $event->getTableNumber(),
]);
}
public function eventType()
{
return TabOpened::class;
}
}

119. <?php
class Projector
{
private $projections = [];
public function register(array $projections)
{
foreach ($projections as $projection) {
$this->projections[$projection->eventType()] = $projection;
}
}
public function project(DomainEvents $events)
{
foreach ($events as $event) {
if (!isset($this->projections[get_class($event)]))
throw new NoProjectionExists();
$this->projections[get_class($event)]->project($event);
}
}
}

120. Modelo lectura

121. Modelo anémico
DTO
Entidades generadas ORM
Repositorios generados ORM
Frameworks

123. There are no dumb questions ...

124. https://github.com/malotor/cafe_events
PHP 7.1
Phpunit 6
Docker

125. ☁ events_cafe [master] tree -L 1
.
├── README.md
├── bootstrap.php
├── build
├── cache
├── cli-config.php
├── composer.json
├── composer.lock
├── coverage
├── docker-compose.yml
├── phpunit.xml
├── public
├── resources
├── scripts
├── src
├── tests
└── vendor

126. ☁ events_cafe [master] tree -L 2 src
src
├── Application
│ ├── Command
│ ├── DataTransformer
│ └── Query
├── Domain
│ ├── Model
│ └── ReadModel
└── Infrastructure
├── CommandBus
├── Persistence
├── Serialize
└── ui

127. ☁ events_cafe [master] tree -L 2 src/Application
src/Application
├── Command
│ ├── CloseTab.php
│ ├── CloseTabHandler.php
│ ├── MarkDrinksServedCommand.php
│ ├── MarkDrinksServedHandler.php
│ ├── MarkFoodServedCommand.php
│ ├── MarkFoodServedHandler.php
│ ├── OpenTabCommand.php
│ ├── OpenTabHandler.php
│ ├── PlaceOrderCommand.php
│ ├── PlaceOrderHandler.php
│ ├── PrepareFoodCommand.php
│ └── PrepareFoodHandler.php
├── DataTransformer
│ ├── DataTranformer.php
│ └── TabToArrayDataTransformer.php
└── Query
├── AllTabsQuery.php
├── AllTabsQueryHandler.php
├── OneTabQuery.php
└── OneTabQueryHandler.php

128. ☁ events_cafe [master] tree -L 4 src/Infrastructure
src/Infrastructure
├── CommandBus
│ └── CustomInflector.php
├── Persistence
│ ├── Domain
│ │ └── Model
│ │ ├── DoctrineOrderedItemRepository.php
│ │ ├── InMemoryTabRepository.php
│ │ └── TabEventSourcingRepository.php
│ ├── EventStore
│ │ ├── EventStore.php
│ │ ├── PDOEventStore.php
│ │ └── RedisEventStore.php
│ └── Projection
│ ├── BaseProjection.php
│ ├── DrinksOrderedProjection.php
│ ├── Projection.php
│ ├── Projector.php
│ ├── TabOpenedProjection.php
│ └── TabProjection.php
├── Serialize
│ ├── JsonSerializer.php
│ └── Serializer.php
└── ui
└── web
└── app.php

129. ☁ events_cafe [master] tree -L 2 src/Domain
src/Domain
├── Model
│ ├── Aggregate
│ ├── Events
│ ├── OrderedItem
│ └── Tab
└── ReadModel
├── Items.php
└── Tabs.php

130. ☁ events_cafe [master] tree -L 2 src/Domain/Model
src/Domain/Model
├── Aggregate
│ ├── Aggregate.php
│ └── AggregateId.php
├── Events
│ ├── DrinksOrdered.php
│ ├── DrinksServed.php
│ ├── FoodOrdered.php
│ ├── FoodPrepared.php
│ ├── FoodServed.php
│ ├── TabClosed.php
│ ├── TabEvent.php
│ └── TabOpened.php
├── OrderedItem
│ ├── OrderedItem.php
│ ├── OrderedItemNotExists.php
│ └── OrderedItemsRepository.php
└── Tab
├── DrinkIsNotOutstanding.php
├── FoodIsNotPrepared.php
├── FoodNotOutstanding.php
├── MustPayEnoughException.php
├── Tab.php
├── TabHasUnservedItems.php
├── TabId.php
├── TabNotExists.php
├── TabNotOpenException.php
└── TabRepository.php

131. <?php
$app->post('/tab', function (Request $request) use ($app) {
// …
$command = new CommandOpenTabCommand(
RamseyUuidUuid::uuid4(),
$data['table'],
$data['waiter']
);
$app['command_bus']->handle($command);
// …
})

132. <?php
$app->get('/tab/{id}', function (Request $request, $id) use ($app)
{
$query = new QueryOneTabQuery($id);
$response = $app['query_bus']->handle($query);
return $app->json([
'tab' => $response
]);
});

133. Gracias y ..

134. Que la fuerza os acompañe.