A web browser can also be used to access transaction programs that operate on a mainframe, such as CICS or IMS applications. Using the COM Transaction Integrator (COMTI) feature, you can develop client/server applications that use web browsers to interact with mainframe transaction systems. Because CICS programs can access DB2 databases, COM Transaction Integrator can also provide programmatic access to DB2 on a mainframe.
Any technique for accessing COM objects from the browser can be used because COM Transaction Integrator creates a standard COM automation server component that acts as a proxy for the mainframe CICS or IMS transaction programs. Figure 14.2 illustrates the components that could be involved in creating a web application that uses server-side scripting to dynamically create objects and invoke methods.
Figure 14.2 Browser access to a host transaction system.
Other applications that use technologies such as Remote Data Services (RDS) and client-side scripting can also be developed. In these scenarios, object creation and method invocation is launched from a client script executed on the server and the RDS control directs records of a recordset back to the client by means of HTTP. Retrieved records can then be bound to a grid control for display purposes. More information on sample applications that use these technologies is available on the SNA Server compact disc, in the Samples folder in the COM Transaction Integrator installation directory.