TWSocketServer
Main page -> ICS component reference -> TWSocketServer and TSslWSocketServer
Contents
Overview
| unit | OverbyteIcsWSocketS.pas | |
| inheritance | TWSocket |
TWSocketServer will normally be used to listen on a given TCP port. When a client connects, it will instantiate a new TWSocketClient component to handle communication with client. Normally you will derive your own component from TWSocketClient to add private data and methods to handle your processing needs. You tell TWSocketServer which component class it has to instantiate using ClientClass property. You have to initialize each instance created to handle each client from OnClientConnect event handler. TWSocketServer maintain a list of connected clients. You can access it using Client[] indexed property. ClientCount property is the size of Client[] array.
Since it is derived from TWSocket and TSslWSocket, lots of properties and events are unused and not listed here. Properties and events that have a meaning in both server or client component are listed here.
Note that TWSocketServer is only usable for incoming TCP connections. Use TWSocket if you need to use UDP.
Note: When a TWSocketClient is closed, it automatically frees itself. With a normal TWSocket, the programmer is responsible for freeing the object.
Properties
| Addr | Server listen IP address, IPv4 or IPv6, maybe 0.0.0.0 or :: to listen on all available addresses, ignored if any IcsHosts specified. IP address must exist and not be in use elsewhere for the same port. | |
| Banner | A short message line sent when each client connects. Should generally be blank. | |
| BannerTooBusy | A short message sent when a client connects and the number of clients already exceeds the MaxClients limit. | |
| Client | Indexed property giving access to all connected clients. | |
| ClientClass | Class the component use to handle each incoming connection. | |
| ClientCount | Number of connected clients. | |
| Handle | Handle of the hidden window used for socket operation. | |
| HSocket | Underlying winsock socket handle. | |
| IcsHosts | Allows one or more TIcsHosts to be set, as TIcsHostCollection, an alternate way for specifying multiple listeners that allows multiple hosts to be specified, each with one or two IP addresses and non-SSL and SSL port bindings, SSL certificates and private key (perhaps combined in a bundle), SSL context and security level, and other web server host related properties (used by higher level components). Each IcsHost has one or more HostNames to which it will recognise, that can share IP addresses. | |
| LastError | Last error which occurred. | |
| ListenBacklog | How many pending connection the system has to accept before denying access. | |
| MaxClients | Max number of connected client. All subsequent connections will be closed. | |
| MultiListenSockets | Allows one or more extra server listen IP addresses and ports to be specified, as type TWSocketMultiListenCollection, allowing server to listen on several IP addresses/ports at the same time, in addition to the that specified as Addr/Port props. Each TWSocketMultiListenItem has Addr, Port, SocketFamily, SslEnable and ListenBacklog properties. Better to use IcsHosts for new applications which does the same, ignored if any IcsHosts specified. | |
| MultiListenIndex | Read only, which listen socket accepted last connection, -1 if default Addr.Poprt used, 0 or above is index into MultiListenSockets collection. | |
| Port | TCP port or service name to listen to, usually 80 or 443, ignored if any IcsHosts specified. | |
| PortNum | Readonly property with numeric value corresponding to Port. | |
| Proto | Protocol used. Must be 'tcp'. | |
| SocketFamily | IP address socket family as TSocketFamily, from sfIPv4, sfIPv6. | |
| SslEnable | True if an SSL connection should be negotiated. ignored if any IcsHosts specified. | |
| SslContext | Assign to an TSslContext component for SSL support, where SSL certificates, keys, protocols and ciphers are specified, ignored if any IcsHosts specified. | |
| State | Gives the state of the component. |
Methods
| Abort | Abort current asynchronous operation. | |
| Close | Stops listening, does not disconnect connected clients. | |
| CloseDelayed | Same as Close however it's executed delayed, after current event has finished. | |
| Create | Create a new instance of the component. | |
| Destroy | Destroy the current instance. | |
| IsClient | Check if a component reference is one of the connected clients. | |
| Listen | Start accepting connections. | |
| MessageLoop | Internal message loop. | |
| MessagePump | Internal message pump. | |
| ProcessMessage | Process a single message. | |
| ProcessMessages | Process messages until message queue is empty. | |
| Release | Destroy the current instance after the current event is terminated. | |
| ThreadAttach | Detach from current thread. | |
| ThreadDetach | Attach to current thread. |
Events
| OnBgException | When a background exception occurs. | |
| OnChangeState | When the component state changes. | |
| OnClientConnect | When a new client is connecting. | |
| OnClientCreate | When a new client component instance is created. | |
| OnClientDisconnect | When a client disconnects. | |
| OnError | When an error occurs. Better to use exception handling. | |
| OnMessagePump | To call your own external message pump instead of built-in one. |
How to
