As a side-project I tried to port Stellar Crisis 2.2 (a 15 year old browser game written in the C-like langage Pike for the Roxen server) to Django. So far, unfortunately, I failed. It seems, Django isn't the right tool to create such kind of application :(
SC keeps all persistent data two global dicts that contain other dicts containing more dicts and arrays. I tried to map the data onto database tables but doing this, most of the elegance of Python seems to vanish. My code is actually worse than the original Pike code. Here's an example (Pike): p[d[series][game]["f"][ixb]["owner"]]["kills"]++; "p" is the global dict of players (all player data are kept in another dict). "d" is the global dict of all other game data. Games are instances of series and "f" probably means fleet and stands for a dict of all ships. A ship is owned by a player and the server stores how many other players a player has beaten. The Django equivalent seems to be: g = Series.objects.get(name=series).game_set.get(no=game) p = Player.objects.get(name=g.fleet_set.get(no=ixb).owner) p.kills += 1 p.save() I want to stay close to the original source code (even if I do not consider it the best style) to make porting the code more straight forward. Therefore, I added helper methods to the models so that I can use [] to access a series' game. The resulting code looks like is: player = p[d[series][game].f(ixb).owner] player.kills += 1 player.save() However, I still need three lines of code where the original just used one line because I have to explicitly save the state change. The original Pike code contains all game logic in one very large function (~800 lines of code) that does a lot of modifications. Adding explicit save() methods all over the place seems to be a bad (and inefficient) way to add persistence. I'd like to freely modify database objects once loaded into memory and then put everything that was modified with just one command back to the database. Most ORMs work that way, I think. Objects are loaded once within a transaction, know whether they are modified, dependent objects can be automatically added or deleted and all modifications of the database take place in one bulk operation at the end of the transaction. Has anybody extended Django's ORM in such a way? Can it be replaced with some other mapper? I recently heard about Storm, a new mapper written by the Ubuntu guys... I'd prefer to not have to write my own ORM. I've done that more than once in other language :) My ad hoc idea is to add a __setattr__ method to all models after their post_init signal and that method would register the model object as modified with some transaction context. However, because Django's ORM doesn't honor object identity, things get very inefficient very soon. I'd also need to overwrite delete() to make sure that I do not save deleted objects. But then, it seems that each time I ask a game for its fleets or systems, a new database query is executed and I have to cache them manually and reset the cache manually if I add new ships or systems. I'm afraid, I over-bend Django's ORM here... -- Stefan Matthias Aust --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Django users" group. To post to this group, send email to django-users@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/django-users?hl=en -~----------~----~----~----~------~----~------~--~---
