ASNA WingsRPG™ Reference Manual

Data Flow

The standard data flow between an RPG program and its display is shown below. When an ILE RPG program reads or writes data from/to a display, file OS/400 APIs are used to route the 5250 display file data from/to the display file.

User view before Wings

ASNA Wings is enabled by an IBM product called Rational Open Access for RPG. Open Access provides the ability for third-party vendors to plug custom file IO "handlers" into the ILE RPG program execution pipeline. See IBM's Rational Open Access RPG Edition for more detail on Open Access. ASNA Wings provides an Open Access Handler to redirect display file IO to ASNA Wings-created browser pages, as shown below.

User view after Wings

With the "ASNAWINGS" Handler installed you create browser-based versions of your existing display files. While creating the new display files you add one line of code to the ILE RPG program to tell it to use the new display files. In a nutshell, that is it!

Internally, the ILE RPG program logic and data file IO aren't aware of this display file change. The program executes as it always did, but when display files are used, they're the new ones.