Subject Re: [IB-Architect] BLOB filters and BLOB types
Author Marcelo Lopez Ruiz
> An Inerbase database file isn't a well defined format in the
> sense that it's a moving target. Also, from an architecture
> point of view, nothing but the engine and possibly a low level
> maintenance utility should ever be aware of the format. Developers
> are, of course, exempted.

I was thinking more along the lines of saving the blob to a temporary file,
having it modified by the current IB engine on the system (whichever it
happens to be), and then saved back into the blob stream. I can see a lot of
holes with this approach, but then again, I can also see quite a number of
uses for it.

I agree it's best if left to developers to implement out of the database
(although a GDB->HTML filter could be very nice...)

> Is there a definitive specification of a Delphi Form File? A fixed
> specification is a necessary prerequisive to a subtype number.

There are two formats: the good ol' binary, and the text format (which is
the new default for D5, but was available before, too). Delphi does have
some mechanism for telling them apart, and I suspect it can probably be
found in the sources (Classes.pas comes to mind, but I'd have to check).

AFAIK, it's not the format that has changed in some essential way, but the
way Delphi can interpret it (e.g.: having the correct run-time classes for
persistance, long vrs. short strings for D1 users, frames, references to
external forms, whatever else I can't think of right now). And this is, of
course, absolutely out of a database server field (altough a 'compiled
package' blob type would be useful, if one were willing to commit to a
specific platform's binary formats).

Marcelo Lopez Ruiz