GXml-GObject Serialisation: Back to the Future

Hello.

Part of the past two weeks has been spent updating my system to a modern environment (Fedora 17) which mean development tool updates (like vala and gee) and updating GXml to support the changes there.  It took me a few days to correctly update the NodeList classes as they were Iterable and had Iterators.  One of which changed a little, and both now require implementing a Traversable interface, which turned out simpler than I originally thought it.  I'm not completely sure that I got the Traversable methods right, but I ended up realising that there were generic implementations that I can hopefully rely on.  GXml still passes its tests which seem sufficient.

Once that was out of the way, I could work on making serialisation code compile and base it off of JsonGLib.  (My first prototype was simple and stupid and built up strings that were then converted to a GXml Document :D.)  The current prototype has code that:

• serialises to XML a GObject with properties (but not its member fields), similar to JsonGLib
• deserialises from XML a GObject (assuming the type is known to the local system)
• has an interface a class can implement to handle serialisation itself

Well, the third one probably doesn't work any more, as the first iteration of the JsonGLib-ish design that was using it was rewritten to work on whole objects right now.  Also, the serialisation and deserialisation of objects support most but not all property types so far (e.g. enums are skipped).

I've been documenting challenges I've been encountering under another category on my blog, #Technology.  Most of them involve bumping my head against Vala and figuring out how some things work in it.  It took me an embarrassing while to realise that GValue's transform and conversion methods will not convert strings to things like ints and doubles.  Whoops.

The goals for this next week are:

• investigate options for serialising non-property fields (if any one has any tips (e.g. GObject Introspections) please note them in a comment :D)
• get the interface into a happy state and tested
• make the auto-serialising code more complete and eliminate compiler warnings

The current prototype code is available in GXml's git repository now.  I'm having severe difficulty bringing myself to publish code that's so rough, especially given the high standard I encounter in GNOME when submitting patches to other projects, and it kept me from sharing prototypes until now, but as I'm being reminded, it'll be more important to have it visible so that people who want to help can.

Cheerio!