Let me add I am worried about concurrency issues with this approach. Where would subclassing be done? Cannot be done in models.
On Aug 19, 9:43 am, Carlos <carlosgali...@gmail.com> wrote: > Hi all, > > Can I propose the following in order to being able to subclass DAL classes?. > > We can currently subclass DAL in our own models and use the new class at DAL > creation time (db = MyDAL(...)), but the problem is that all other classes > are internally and directly instantiated in DAL.py. > > So let's just start with Table for now. > > In DAL.__init__, insert the following as the first line: > > self.cls = dict(table=Table) > > This 'cls' dict will eventually hold all classes (default or > overridden/custom) to instantiate within DAL.py, all accessible via the DAL > instance, and starting with only table for now: db.cls['table']. > > Then in DAL.define_table, replace the direct "Table" reference with: > > self.cls['table'] > > So far all other direct references to Table in DAL.py are for > "isinstance(...,Table)", which will evaluate to True for the Table > subclasses anyways. > > This way we can now modify db.cls dict (for 'table') and have DAL.py > instantiate that class in define_table. > > So in our models, immediately after creating a new DAL instance (or its > custom subclass), we can do the following: > > db.cls['table'] = MyTable > > Ideally all other DAL classes (Set, Rows, Row, Reference, etc.) will > eventually follow this method, using the db.cls dict. > > Another approach is to have direct instance vars in DAL (e.g. cls_table), > instead of going through a 'cls' dict, but that would be up to Massimo. > > What do you think?, can this go into trunk?. > > Thanks, > > Carlos
