Dispatching Queries

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