Progress
External Program
Interfaces
Server Socket and Socket Objects
To enable 4GL applications to access sockets, Progress supports two types of objects:
- Server socket objects — A 4GL object that a socket server creates only to listen for client connection requests. A 4GL socket server receives notification of client connections in the form of events.
- Socket objects — A 4GL object that represents a TCP/IP socket. TCP/IP sockets are the communication endpoints of a connection. Both socket clients and servers use socket objects to read and write data on a connection. In the 4GL, a socket application can detect the arrival of data on a socket in the form of events. (However, this is not required.)
Using Sockets
Using methods on the socket object, a 4GL application can write and read any available data on a socket at any time, as long as the socket connection is active. Thus, the application can detect the arrival of data using events or not, depending on application requirements.
Both socket and server socket handles provide a variety of additional methods and attributes that you can use to monitor and control socket communications. For example, you can temporarily disable events on a socket object to run more efficiently when a client or server does not need to receive data on the connection. You can also temporarily or permanently disable events on a server socket when you no longer want the server to respond to client connection requests. Other methods and attributes allow you to set and monitor additional socket communications options and conditions.
Copyright © 2004 Progress Software Corporation www.progress.com Voice: (781) 280-4000 Fax: (781) 280-4095 |