An RPG program can use the Universal Display File handler by declaring a Universal Display File in the program with HANDLER keyword, as shown here:
The Universal Display File Handler supports only the following operations:
Any other operation will result in an I/O error being received by the RPG program.
When a WRITE operation is performed, the record format’s static content will be combined with the current field data from RPG, and the content will be written to either HTTP or file output, depending on the “destination” property on the record format. A READ operation is only valid when running in the Web Connector, HTTP input parameters can be received.
RPG coding considerations are different for running in the Web Connector, vs. standard program call.