Specifying a Connection Using HTTP

You can establish a connection to the application server using HTTP from any machine that has a TCP/IP address. Unlike sockets, however, HTTP allows you to take advantage of SSL security and to communicate with a server that is protected behind a firewall. When using HTTP, include a TWebConnection component for connecting to the application server.

The Web connection component establishes a connection to the Web server application (httpsrvr.dll), which in turn communicates with the application server. TWebConnection locates httpsrvr.dll using a Uniform Resource Locator (URL). The URL specifies the protocol (http or, if you are using SSL security, https), the host name for the machine that runs the Web server and httpsrvr.dll, and the path to the Web server application (httpsrvr.dll). Specify this value using the URL property.

Note: When using TWebConnection, wininet.dll must be installed on the client machine. If you have IE3 or higher installed, wininet.dll can be found in the Windows system directory.

If the Web server requires authentication, or if you are using a proxy server that requires authentication, you must set the values of the UserName and Password properties so that the connection component can log on.

If you have multiple servers that your client application can choose from, you can use the ObjectBroker property instead of specifying a value for URL. For more information, see Brokering connections.