Re: [boost] [Boost Review] Property Tree Library

From: Gennadiy Rozental (gennadiy.rozental_at_[hidden])
Date: 2006-04-21 22:02:45

"Marcin Kalicinski" <kalita_at_[hidden]> wrote in message 
news:e2bho8$c7e$1_at_sea.gmane.org...
>> Use Serialization lib for this.
>>
>>> But some values are also only human editable (not on the system setup
>>> display etc) so simple XML based files work well because they can easily
>>> be read/written by a person and the software itself.
>>
>> There many ways to deal with it. For example you could keep these fields 
>> as strings in memory or use separate storage for them or teach 
>> boost::serialization to save/load them.
>
> I have recently tried to do just this. Not subtracting from the great 
> value of serialization library, it has a nasty habit of polluting XML 
> files it generates with all sorts of magic id numbers that definitly are 
> not human editable or creatable. By creating my own archive class I was 
> able to get rid of most of them, but not all. Some (class-id integers and 
> tracking-id integers) are so inherently embedded in the library that it 
> would require quite an effort to hack them out.
>
> To be able to hand-edit XML serialization files, I needed to replace 
> class-id integers with class names (the ones you specify to 
> BOOST_SERIALIZATION_EXPORT macros). Initially I thought it will be easy, 
> but I was wrong. Entire dynamic instantiation mechanism in serialization 
> library seems to depend heavily on these integer ids. It only uses names 
> when class is first seen, and there is not id for it yet. I then tried to 
> use sure-fire method ;-) , which failed as well. Briefly, I made my 
> archive class to generate fake class-ids from class names (in an effort to 
> predict which id would be expected now by serialization). It failed for 
> reasons I cannot recall at the moment - they had something to do with 
> inheritance hierarchies.
>
> In case of tracking-ids I just wanted them out, because I do not have 
> duplicate objects in human-created files. On the other hand, I couldn't 
> disable tracking per-class, because I still wanted other archives to do 
> tracking on these objects. A couple of days ago I even posted a question 
> for Robert, and he says that I would need to create my own version of 
> tracking.hpp.
>
> So as you can see it is not all roses with serialization library and human 
> readable files.

Well you need to bring it all to the Robert attention. Boost serialization 
should support wide variety of archives, including simple xml.

Gennadiy