TsgcWSPServer_WAMP › Events › OnSubscription

OnSubscription Event

Fires after a client subscription has been accepted and the broker has registered the client against the topic.

Syntax

property OnSubscription: TsgcWSSubscriptionEvent;
// TsgcWSSubscriptionEvent = procedure(Connection: TsgcWSConnection; const Subscription: String) of object

Default Value

—

Remarks

Runs immediately after OnBeforeSubscription returned Accept := True and the internal broker table has been updated. Subscription is the canonical topic URI. This is the right place to publish a welcome event to the newly-subscribed client (via the Event method) or to emit audit/metric records that a client has joined a topic. The handler is informational only — there is no way to cancel the subscription from here, use OnBeforeSubscription for access control.

Example

procedure TForm1.WAMPServerSubscription(Connection: TsgcWSConnection;
  const Subscription: String);
begin
  Memo1.Lines.Add(Format('[%s] joined %s', [Connection.Guid, Subscription]));
  // push a current snapshot to the new subscriber only
  WSPServerWAMP1.Event(Subscription, '{"snapshot":true}');
end;

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