Re: [Boost-users] Editable XML Serialization

Subject: Re: [Boost-users] Editable XML Serialization
From: Anne van Rossum (anne_at_[hidden])
Date: 2010-09-15 17:25:20

Robert Ramey <ramey <at> rrsd.com> writes:

> 
> Anne van Rossum wrote:
> > Dear list members,
> >
> > I guess it's one of the hardest search terms around but I would like
> > to know if there is any editable XML serialization provided by Boost
> > or other C++ libraries. And I don't mean the kind of thing that
> > requires you to go jumping around through trees, with iterators etc.
> > I don't want to see any iterator!
> >
> > I really iike the XML serialization method that boost::serialization
> > provides:
> 
> A rich subject which comes up from time to time.  Here are a few
> miscelleaneous observations.
> 
> a) Most of the time what people want when they ask this question is
> 
> xml_in >> my data structure for some arbitrarily defined structure.  Of
> course after you become familiar with the library, it's easy to see that
> this is not possible.  It's annoying to me how often this is stated as
> a failing of the library.

What I want "at the C++ side" so to say, is just the same as with
boost::serialization. That supports already "custom" data structures, because in
the serialize(Archive & ar,...) routine it is possible to define what fields to
write/read. I am not talking about marshalling / unmarshalling to entire
objects. Serializing arbitrary data structures does not make sense to me.

However, I am not familiar with the library, so perhaps I misunderstood you.
Forgive me, I just encountered it today.

> 
> b) It is possble to so some limited editing of xml (or other
> archives) but this would be an ad hoc procedure subject to
> errors.  you might change a value here and there but the minute
> you change something tracked or add a value to a collection
> or whatever, you're not going to be able to keep things consistent.
> I guess you're familiar with this.

Yes.

> 
> I've thought about this alot.  Here are some ideas that I thought
> about.
> 
> a) create an xml_archive along with an xml schema which would
> be friendly with known xml editors.  I thought about this alot an
> concluded that it would be too much like training an ant to train
> a flea.  I don't think it would be possible to make a bunch of
> rules that an xml editor could follow and guarentee that that
> the resulting C++ data object would be correct.  Even it were
> possible, one would likely have to add a bunch of "helper"
> information to get it right.  It would be hard to use, easy to misuse,
> and a maintainence (and support) nightmare.
> 
> So what I want to do is to make the following:
> 
> edit_oarchive<widgets_library>
> edit_iarchive<widgets_library>
> 
> The usage would be the following:
> 
> edit_archive<mfc_widgets> ea
> ...
> ea << my_data

That's a solution. I would then need to distribute a separate binary to
manipulate the XML files. My idea was to "misuse" boost::serialization for
writing XML configuration files without the need to manually build DOM-like
structures. For just changing configuration parameters, a graphical solution
might be a bit cumbersome. It's a nice idea nevertheless!

> Robert Ramey
> 

Anne