TsgcWebSocketHTTPServer Events

Events you can handle, grouped by purpose, followed by the full alphabetical list.

Lifecycle

Name	Description
OnStartup	Fires after the server has started and is ready to accept connections.
OnShutdown	Fires after the server has stopped and no more connections are accepted.
OnTCPConnect	Fires after a client connects at TCP level and before the WebSocket handshake, so the connection can be accepted or rejected.
OnConnect	Fires every time a WebSocket connection is established with a client.
OnDisconnect	Fires every time a WebSocket connection with a client is dropped.
OnHandshake	Fires after the handshake is evaluated on the server side and before the response is sent.
OnError	Fires whenever a WebSocket protocol error occurs, such as a mal-formed handshake.
OnException	Fires whenever an unhandled exception is raised while processing a client connection.
OnUnknownProtocol	Fires when the first message does not match a known protocol so the connection can be accepted or rejected.
OnUnknownAuthentication	Fires when authentication is enabled and the authentication method is not recognized by the server.

Data

Name	Description
OnMessage	Fires every time a client sends a text message and it is received by the server.
OnBinary	Fires every time a client sends a binary message and it is received by the server.
OnFragmented	Fires when a fragment of a message is received (only when Options.FragmentedMessages is frgAll or frgOnlyFragmented).

HTTP

Name	Description
OnBeforeCommand	Fires before OnCommandGet or OnCommandOther so the request can be screened, authorized, or short-circuited with a 401 response.
OnCommandGet	Fires when the HTTP server receives a GET, POST, or HEAD request so the application can build the response.
OnCommandOther	Fires when the HTTP server receives a method other than GET, POST or HEAD (PUT, DELETE, OPTIONS, PATCH...).
OnBeforeForwardHTTP	Fires before an HTTP request is dispatched so it can be forwarded (reverse-proxied) to another HTTP server.
OnAfterForwardHTTP	Fires after an HTTP request has been forwarded so the application can inspect the result or an error returned by the upstream server.
OnHTTP2BeforeAsyncRequest	Fires before an HTTP/2 request is queued so the application can choose whether it runs in the pool of threads or in the connection thread.

Sessions

Name	Description
OnCreateSession	Fires when the HTTP server needs to create a new session so the application can supply a custom TIdHTTPSession instance.
OnSessionStart	Fires when an HTTP session is started and added to the SessionList.
OnSessionEnd	Fires when an HTTP session is closed, either explicitly or after SessionTimeout expires.
OnInvalidSession	Fires when an HTTP request presents an unknown or expired session ID so the application can decide how to react.

HTTP Upload

Name	Description
OnHTTPUploadBeforeSaveFile	Fires before a file extracted from a multipart/form-data upload is saved to disk so the name and path can be customized.
OnHTTPUploadAfterSaveFile	Fires after a file extracted from a multipart/form-data upload has been saved to disk.
OnHTTPUploadReadInput	Fires when the multipart/form-data decoder reads a non-file input field so its value can be captured.
OnHTTPUploadBeforeCreatePostStream	Fires after the request headers have been read and before the POST stream is created so the upload can be accepted or rejected.

Reliability

Name	Description
OnBeforeHeartBeat	Fires before each HeartBeat ping so the application can implement a custom keep-alive.
OnLoadBalancerConnect	Fires when the server connects to the Load Balancer Server.
OnLoadBalancerDisconnect	Fires when the server disconnects from the Load Balancer Server.
OnLoadBalancerError	Fires when an error occurs communicating with the Load Balancer Server.

Security

Name	Description
OnAuthentication	Fires when authentication is enabled so the application can check user and password and accept or reject the connection.
OnSSLGetHandler	Fires before the SSL handler is created so a custom server-side handler instance can be supplied.
OnSSLAfterCreateHandler	Fires after the SSL handler has been created so its properties can be customized.
OnSSLALPNSelect	Fires during an ALPN-enabled handshake so the application can pick which protocol to negotiate.
OnSSLVerifyPeer	Fires when VerifyCertificate is enabled and the client presents a certificate to be accepted or rejected.

All Events (alphabetical)

Name	Description
OnAfterForwardHTTP	Fires after an HTTP request has been forwarded so the application can inspect the result or an error returned by the upstream server.
OnAuthentication	Fires when authentication is enabled so the application can check user and password and accept or reject the connection.
OnBeforeCommand	Fires before OnCommandGet or OnCommandOther so the request can be screened, authorized, or short-circuited with a 401 response.
OnBeforeForwardHTTP	Fires before an HTTP request is dispatched so it can be forwarded (reverse-proxied) to another HTTP server.
OnBeforeHeartBeat	Fires before each HeartBeat ping so the application can implement a custom keep-alive.
OnBinary	Fires every time a client sends a binary message and it is received by the server.
OnCommandGet	Fires when the HTTP server receives a GET, POST, or HEAD request so the application can build the response.
OnCommandOther	Fires when the HTTP server receives a method other than GET, POST or HEAD (PUT, DELETE, OPTIONS, PATCH...).
OnConnect	Fires every time a WebSocket connection is established with a client.
OnCreateSession	Fires when the HTTP server needs to create a new session so the application can supply a custom TIdHTTPSession instance.
OnDisconnect	Fires every time a WebSocket connection with a client is dropped.
OnError	Fires whenever a WebSocket protocol error occurs, such as a mal-formed handshake.
OnException	Fires whenever an unhandled exception is raised while processing a client connection.
OnFragmented	Fires when a fragment of a message is received (only when Options.FragmentedMessages is frgAll or frgOnlyFragmented).
OnHandshake	Fires after the handshake is evaluated on the server side and before the response is sent.
OnHTTP2BeforeAsyncRequest	Fires before an HTTP/2 request is queued so the application can choose whether it runs in the pool of threads or in the connection thread.
OnHTTPUploadAfterSaveFile	Fires after a file extracted from a multipart/form-data upload has been saved to disk.
OnHTTPUploadBeforeCreatePostStream	Fires after the request headers have been read and before the POST stream is created so the upload can be accepted or rejected.
OnHTTPUploadBeforeSaveFile	Fires before a file extracted from a multipart/form-data upload is saved to disk so the name and path can be customized.
OnHTTPUploadReadInput	Fires when the multipart/form-data decoder reads a non-file input field so its value can be captured.
OnInvalidSession	Fires when an HTTP request presents an unknown or expired session ID so the application can decide how to react.
OnLoadBalancerConnect	Fires when the server connects to the Load Balancer Server.
OnLoadBalancerDisconnect	Fires when the server disconnects from the Load Balancer Server.
OnLoadBalancerError	Fires when an error occurs communicating with the Load Balancer Server.
OnMessage	Fires every time a client sends a text message and it is received by the server.
OnSessionEnd	Fires when an HTTP session is closed, either explicitly or after SessionTimeout expires.
OnSessionStart	Fires when an HTTP session is started and added to the SessionList.
OnShutdown	Fires after the server has stopped and no more connections are accepted.
OnSSLAfterCreateHandler	Fires after the SSL handler has been created so its properties can be customized.
OnSSLALPNSelect	Fires during an ALPN-enabled handshake so the application can pick which protocol to negotiate.
OnSSLGetHandler	Fires before the SSL handler is created so a custom server-side handler instance can be supplied.
OnSSLVerifyPeer	Fires when VerifyCertificate is enabled and the client presents a certificate to be accepted or rejected.
OnStartup	Fires after the server has started and is ready to accept connections.
OnTCPConnect	Fires after a client connects at TCP level and before the WebSocket handshake, so the connection can be accepted or rejected.
OnUnknownAuthentication	Fires when authentication is enabled and the authentication method is not recognized by the server.
OnUnknownProtocol	Fires when the first message does not match a known protocol so the connection can be accepted or rejected.