Re: Use of XML for config files

[Darren New <dnew@san.rr.com>]

Stephen Leake wrote:
> I agree with this; I'm not sure how to put comments in the API.

I would carry a possibly-empty string for each key and section. Allow calls
to set or retrieve the comment for a particular key or section.
 
> > Well, that's the question. I think it's something much easier to
> > answer for INI files than XML files.
> 
> Ok, could you provide an example implementation? I'll be posting a
> Java properties style after the weekend, without comments. Maybe you
> could start with that.

I'll look, but I'm kind of busy. :-)
 
> > Uh, sure it does. The order of tags in XML is quite explicitly important.
> 
> Well, the order of data tag 'foo' vs comment tag 'bar' is not
> important, unless the DTD says it is.

Fair enough. But if the order isn't important in the DTD, then you can't
tell what item the comment refers to, so the order *becomes* important, in
the sense that the API has to say where in the list of things output to the
file the comments belong.

<foo>
  <comment> This is the color </comment>
  <color> red </color>
  <comment> This is the brightness </comment>
  <brightness> 54% </brightness>
</foo>

What's the DTD for foo?
<!ELEMENT foo (comment|color|brightness)>
Even if the DTD says the order is unimportant, the order is important. :-)

> Ok, I like that. It breaks your earlier example where you had a
> comment following a value, but we can't have everything.

I don't think that was *my* example, but OK. You could also make it follow
the value if it fit. That's the advantage of attaching it to a key instead
of to some position in a list.
 
> > I'm just saying that I think the semantics of the kind of thing an INI file
> > would have to deal with in the API are pretty darn straightforward.
> 
> I bet we could come up with an implementation of the same semantics
> for XML.

But then why use XML if it's just going to make it more complex without
giving you any more powerful semantics?
 
> Note that neither of these semantics will support arbitrary placement
> of comments by direct editing; the user has to know the rules.

Well... the rule is that the comment talks about the next thing. :-)
 
> > The kinds of things an XML-based file would have to deal with are
> > far more complicated.
> 
> But we don't have to support them all.

You have to certainly at least detect them. And if you're not going to
support them, why use XML?

-- 
Darren New 
San Diego, CA, USA (PST). Cryptokeys on demand.
** http://home.san.rr.com/dnew/DNResume.html **
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     My brain needs a "back" button so I can
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