TsgcWSPClient_STOMP_ActiveMQ › Events › OnActiveMQMessage

OnActiveMQMessage Event

Fires when a MESSAGE frame is received for an active ActiveMQ subscription; delivers the body, the typed Headers and the originating Subscription item.

Syntax

property OnActiveMQMessage: TsgcWSActiveMQSTOMPMessageEvent;
// TsgcWSActiveMQSTOMPMessageEvent = procedure(Connection: TsgcWSConnection; MessageText: String; Headers: TsgcWSActiveMQSTOMPHeadersMessage; Subscription: TsgcWSBrokerSTOMPSubscriptionItem) of object

Default Value

—

Remarks

Raised every time the ActiveMQ broker dispatches a MESSAGE frame to one of the client's subscriptions. Parameters:

• MessageText — the body of the MESSAGE frame (the payload delivered by the publisher).
• Headers — a TsgcWSActiveMQSTOMPHeadersMessage object exposing Destination, MessageId (unique identifier assigned by the broker, required when calling ACK or NACK), Subscription id, ACK value (present only when the subscription uses client or client-individual acknowledgment mode; the handler MUST call ACK or NACK passing this value), ContentType, plus the ActiveMQ-specific Expires, Priority and Timestamp properties and the complete RawHeaders string with all user-defined and vendor-specific headers.
• Subscription — the TsgcWSBrokerSTOMPSubscriptionItem that received the message, matching the entry returned by Subscribe.

Example

procedure TForm1.ActiveMQMessage(Connection: TsgcWSConnection;
  MessageText: String; Headers: TsgcWSActiveMQSTOMPHeadersMessage;
  Subscription: TsgcWSBrokerSTOMPSubscriptionItem);
begin
  Memo1.Lines.Add(Format('[%s] %s', [Headers.Destination, MessageText]));

  // acknowledge when the subscription requires it
  if Headers.ACK <> '' then
    ActiveMQ.ACK(Headers.MessageId, Headers.Subscription);
end;

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