TsgcWebSocketProxyServer › Methods › Ping
Sends a WebSocket ping frame to every connected client on the browser-facing side of the proxy.
procedure Ping(const aText: string = '');| Name | Type | Description |
|---|---|---|
aText | const string | Optional payload to carry inside the ping frame; pass an empty string to send a ping with no payload. |
Ping iterates the active WebSocket connection list and sends a WebSocket ping frame to each client, returning once the frames are handed to the underlying sockets. The ping only targets the WebSocket side of each tunnel, since the paired upstream TCP connection is a raw byte stream that does not carry WebSocket control frames. It is a convenient way to keep idle browser connections alive or to probe liveness manually. Any pong replies are delivered asynchronously through the standard connection events and exceptions raised while writing are routed to OnException.
oServer.Ping('keepalive');