Re: config files proposal

[Stephen Leake <stephen_leake@acm.org>]

Darren New <dnew@san.rr.com> writes:

> Stephen Leake wrote:
> > > You need to specify where a file is written in the path. (API#6)
> > > apparently only talks about reading files.
> > 
> > It should be written where it is found; I'll add that. Hmm, special
> > case if it is a new file; write it to the first directory in the
> > search path.
> 
> The problem here is if you load a system-wide config file, make changes, and
> want to save it. You at least need a routine that says "pretend you got it
> from *here*" or something; i.e., to change the name&path of the file between
> reading and writing.

Good point. I guess I can check the write privs on the found file. 

Or provide two search paths; one read-only and one writeable.

> > > Question: Are keys case-sensitive?
> > 
> > Good point. I think I'll go with the Ada identifier model and say
> > "no".
> 
> If "no" and you're allowing Unicode, then you have to worry about the
> bizarre transformations that some languages have.

yes. And Glib.XML is case sensitive. Although Glib.XML also uses
String for Tags, not Wide_String. So I have to check the XML
definition; does it allow Wide_String for tags? Hmm.
http://www.w3.org/TR/2000/REC-xml-20001006#NT-Letter seems to imply 16
bit characters, but I'm not clear on whether it's UniCode or something
else. There's also the issue of what Wide_Text_IO actually writes.

> > base64 would be good for values that don't need to be user editable. I
> > guess persistent storage for a large object (whether it is composite
> > or not) could be supported that way. I'm not clear why that would be
> > in a typical "config file". Hmm, maybe a pixel bitmap for an icon?
> 
> That was actually my thought, yes. Funky how we both had the same example in
> mind.

Yes. However, a better solution for bitmaps is to keep the bitmap in a
file that a bitmap editor will recognize, and put the path to it
(possibly relative) in the config file. 

But we don't need to _forbid_ binary data in the config file, if it's
not hard to do.

-- 
-- Stephe