Client Access
The OpenROAD Server is designed primarily to let you quickly write your business logic in 4GL and then share that business logic across a wide variety of clients, including 4GL, COM, Java, and .NET. The OpenROAD Server, with its high performance capabilities for session pooling, load balancing, and failover, provides the perfect container for implementing reusable business logic that can be shared among applications independent of how the functionality is delivered to clients.
OpenROAD Clients
In an OpenROAD client, the complexities of driving the COM interface are hidden within a 4GL system class, RemoteServer. The RemoteServer system class lets you invoke procedures on an active OpenROAD Server by providing a required procedure name and optional parameters. When the procedure is complete, you can view the status returned.
This simple way of accessing the OpenROAD Server is unique to 4GL clients and consistent with the productivity benefits available when using 4GL in general. It is the backbone for building multi-tier OpenROAD applications.
Java and .NET Clients
The Java and .NET interfaces to the OpenROAD Server provide an easy way for programs written in Java or C# to access 4GL business logic executed in an OpenROAD Server.
The Java and .NET interfaces simplify the connectivity between Java or C# and OpenROAD by providing an interface that is integrated with OpenROAD, and exposes a consistent external interface on all supported platforms.
Although the Java and .NET interfaces to the OpenROAD Server are intended to be reflections of (and consistent with) the underlying COM interface, there are some areas where they are different. For more information, see the Server Reference Guide.
How JSP, ASP .NET, and Other Browser Clients Work
Providing client access to OpenROAD Server business logic using traditional web applications with server-side scripting environments such as JSP and ASP.NET is an integral part of OpenROAD’s functionality. Calling the OpenROAD Server from these environments is similar to driving it from an OpenROAD client. The sequence of calls made and the basic programming logic are identical and include the following steps:
1. Make a connection to the OpenROAD Server application using a client ASOSession COM helper object.
2. Call an SCP to pass parameters to and then execute and extract the results from the business logic in the server.
3. Release the connection to the server when done.
Placing business logic in the 4GL code rather than SQL in the server-side scripts maintains independence between the database schema and the client applications. This increases application and database flexibility over the life of the system.