Re: Report API and Catalog

[Nathan Andelin <nandelin@xxxxxxxxxxxx>]

> Roger Harman wrote:
> I'd really like to see an article or other info on those OO
> techniques.

Briefly consider a statement like:

report.object = rptOpen('XCD500');

Behind the scenes, rptOpen() creates a new instance of a report object 
and returns a pointer to it.  The object has a bunch of properties (an 
integer for storing the number of pages, a string for storing the name 
of the output stream file that's created, and so forth).  One or more 
HTML files associated with the report ID are loaded into memory, and 
parsed into records and fields.

Since you never know how many records or fields there may be in an HTML 
file, rptOpen() allocates memory dynamically for each, and links them 
together in a chain (linked lists).

The pointer returned by rptOpen() becomes a basis for referencing every 
other object in the chain.

In a program that generates multiple reports, you can call rptOpen() 
multiple times.  New report objects are dynamically instantiated with 
each call.

rptClose() destroys all objects created by rptOpen() and frees related 
memory.

The thought process may be somewhat non-traditional, but RPG is still 
well suited for it.

Nathan.