Dispatching Commands

Previous pages provide the background on how to handle command messages in your application. The dispatching process is the starting point for command message.
Command Bus
Command Bus is special type of Messaging Gateway. 
namespace Ecotone\Modelling;
​
interface CommandBus
{
    1 public function send(object $command);
​
    2 public function sendWithMetadata(object $command, array $metadata);
​
    3 public function convertAndSend(string $name, string $sourceMediaType, $commandData);
​
    4 public function convertAndSendWithMetadata(string $name, string $sourceMediaType, $commandData, array $metadata);
}
Send method
Command is routed to the Handler by class type.
Symfony
Lite
Symfony
// Command Bus will be auto registered in Depedency Container.
​
use Symfony\Component\HttpFoundation\Response;
use Symfony\Component\HttpFoundation\Request;
use Ecotone\Modelling\CommandBus;
​
class TicketController
{
   private CommandBus $commandBus;
​
   public function __construct(CommandBus $commandBus)
   {
       $this->commandBus = $commandBus;   
   }
   
   public function closeTicketAction(Request $request) : Response
   {
      $this->commandBus->send(
         new CloseTicketCommand($request->get("ticketId"))
      );
   }
}
Lite
use Ecotone\Modelling\CommandBus;
​
$commandBus = $messagingSystem->getGatewayByName(CommandBus::class);
​
$commandBus->send(new CloseTicketCommand($ticketId));
Command Handler
Command Handler
use Ecotone\Messaging\Annotation\MessageEndpoint;
use Ecotone\Modelling\Annotation\CommandHandler;
​
/**
 *  @MessageEndpoint()
 */
class CloseTicketCommandHandler
{   
    /**
    * @CommandHandler()
    */
    public function closeTicket(CloseTicketCommand $command)
    {
//        handle closing ticket
    }   
}
SendWithMetadata
Does allow for passing extra meta information, that can be used on targeted Command Handler.
Symfony
Lite
Symfony
// Command Bus will be auto registered in Depedency Container.
​
use Symfony\Component\HttpFoundation\Response;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\Security\Core\Security;
use Ecotone\Modelling\CommandBus;
​
class TicketController
{
   private CommandBus $commandBus;
​
   public function __construct(CommandBus $commandBus)
   {
       $this->commandBus = $commandBus;   
   }
   
   public function closeTicketAction(Request $request, Security $security) : Response
   {
      $this->commandBus->sendWithMetadata(
         new CloseTicketCommand($request->get("ticketId")),
         ["executorUsername" => $security->getUser()->getUsername()]
      );
   }
}
Lite
use Ecotone\Modelling\CommandBus;
​
$commandBus = $messagingSystem->getGatewayByName(CommandBus::class);
​
$commandBus->sendWithMetadata(
   new CloseTicketCommand($ticketId),
   ["executorUsername" => $executorUsername]
);
Command Handler
Command Handler
use Ecotone\Messaging\Annotation\MessageEndpoint;
use Ecotone\Modelling\Annotation\CommandHandler;
​
/**
 *  @MessageEndpoint()
 */
class CloseTicketCommandHandler
{   
    /**
    * @CommandHandler()
    */
    public function closeTicket(CloseTicketCommand $command, array $metadata)
    {
          $ticket = ; // get Ticket using command
    
          if ($metadata["executorUsername"] !== $ticket->getOwner()) {
             throw new \InvalidArgumentException("Insufficient permissions")
          }
//        handle closing ticket
    }   
}
ConvertAndSend
Is used with Command Handlers, routed by name and converted using Converter if needed.
Symfony
Lite
Symfony
// Command Bus will be auto registered in Depedency Container.
​
use Symfony\Component\HttpFoundation\Response;
use Symfony\Component\HttpFoundation\Request;
use Ecotone\Modelling\CommandBus;
​
class TicketController
{
   private CommandBus $commandBus;
​
   public function __construct(CommandBus $commandBus)
   {
       $this->commandBus = $commandBus;   
   }
   
   public function closeTicketAction(Request $request) : Response
   {
      $commandBus->convertAndSend("closeTicket", "application/json", '{"ticketId": 123}');
   }
}
Lite
use Ecotone\Modelling\CommandBus;
​
$commandBus = $messagingSystem->getGatewayByName(CommandBus::class);
​
$commandBus->convertAndSend(
   "closeTicket", 
   "application/json", 
   '{"ticketId": 123}'
);
Command Handler
Command Handler
use Ecotone\Messaging\Annotation\MessageEndpoint;
use Ecotone\Modelling\Annotation\CommandHandler;
​
/**
 *  @MessageEndpoint()
 */
class CloseTicketCommandHandler
{   
    /**
    * @CommandHandler(inputChannelName="closeTicket")
    */
    public function closeTicket(CloseTicketCommand $command)
    {
//        handle closing ticket
    }   
}
ConvertAndSendWithMetadata
Symfony
Lite
Symfony
// Command Bus will be auto registered in Depedency Container.
​
use Symfony\Component\HttpFoundation\Response;
use Symfony\Component\HttpFoundation\Request;
use Ecotone\Modelling\CommandBus;
​
class TicketController
{
   private CommandBus $commandBus;
​
   public function __construct(CommandBus $commandBus)
   {
       $this->commandBus = $commandBus;   
   }
   
   public function closeTicketAction(Request $request) : Response
   {
      $commandBus->convertAndSendWithMetadata(
         "closeTicket", 
         "application/json", 
         '{"ticketId": 123}', 
         ["executorUsername" => $executorUsername]
      );
   }
}
Lite
use Ecotone\Modelling\CommandBus;
​
$commandBus = $messagingSystem->getGatewayByName(CommandBus::class);
​
$commandBus->convertAndSendWithMetadata(
   "closeTicket", 
   "application/json", 
   '{"ticketId": 123}',
   ["executorUsername" => "someUsername"]
);
Command Handler
Command Handler
use Ecotone\Modelling\Annotation\CommandHandler;
​
/**
 *  @MessageEndpoint()
 */
class CloseTicketCommandHandler
{   
    /**
    * @CommandHandler()
    */
    public function closeTicket(CloseTicketCommand $command, array $metadata)
    {
          $ticket = ; // get Ticket using command
    
          if ($metadata["executorUsername"] !== $ticket->getOwner()) {
             throw new \InvalidArgumentException("Insufficient permissions")
          }
//        handle closing ticket
    }   
}
Repository
Next - Modelling
Query Handling
Last updated 10 months ago