TsgcWebSocketServer › Events › OnBeforeHeartBeat

OnBeforeHeartBeat Event

Fires before each HeartBeat ping so the application can implement a custom keep-alive.

Syntax

property OnBeforeHeartBeat: TsgcWSOnBeforeHeartBeatEvent;
// TsgcWSOnBeforeHeartBeatEvent = procedure(Sender: TObject; const Connection: TsgcWSConnection; var Handled: Boolean) of object

Default Value

—

Remarks

When HeartBeat is enabled the server sends a standard WebSocket ping to every connected client every HeartBeat.Interval seconds. OnBeforeHeartBeat is raised immediately before that ping is written for each connection so the application can emit its own keep-alive payload on the supplied Connection. Setting Handled to True suppresses the default ping for this cycle; leaving it False (the default) lets the standard ping be sent after the handler returns. Use it to implement protocol-specific heartbeats or to vary the payload per connection.

Example

procedure OnBeforeHeartBeat(Sender: TObject; const Connection: TsgcWSConnection;
  var Handled: Boolean);
begin
  Connection.WriteData('ping');
  Handled := True;
end;

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