HeartBeat

Supported by

 

  TsgcWebSocketServer

  TsgcWebSocketHTTPServer

  TsgcWebSocketServer_HTTPAPI

  TsgcWebSocketClient

 

On Server components, automatically sends a ping to all active WebSocket connections every x seconds.

 

On Client components, automatically sends a ping to the server every x seconds.

 

HeartBeat has the following properties:

 

• Enabled: if true, sends a ping
• Interval: is the value in seconds when a ping will be sent. Example: if value is 10, a ping will be sent every 10 seconds
• Timeout: is the time will wait a response from server. Example: if value is 30, means will wait 30 seconds to receive a response before close connection.
• HeartBeatType: allows customizing how the HeartBeat works
  • hbtAlways: sends a ping every x seconds defined in the Interval.
  • hbtOnlyIfNoMsgRcvInterval: sends a ping every x seconds only if no messages has been received during the latest x seconds defined in the Interval property.

 

 

Customize HeartBeat

 

Client and server components allow customization of HeartBeat to send custom pings and check that the connection is still alive. The event OnBeforeHeartBeat is built exactly for that; it allows you to send a custom message and/or not send the standard ping.

 

Example: send a message text as a ping every 30 seconds.

 

void OnBeforeHeartBeat(TObject Sender; const TsgcWSConnection Connection; ref bool Handled)
{
  Connection.WriteData("ping");
  Handled = true;
}