Re: [SQLObject] API Redesign for 0.6

[Ian B. <ia...@co...>]

Ian Sparks wrote:
>> Ian Bicking wrote on Monday, January 19, 2004 10:38 PM : By using
>> descriptors, introspection should become a bit easier -- or at
>> least more uniform with respect to other new-style classes. Various
>> class-wide indexes of columns will still be necessary, but these
>> should be able to remain mostly private.
> 
> Sorry to pull out just this one part of your plan but its not clear
> to me how you do introspection on current table classes to say, find
> out what columns a table has. This would be useful for generating
> editing web-pages for SO Objects for instance. Being able to walk
> joins would also be helpful so that you could have master/detail
> relationships or populate combo-boxes of all possible values for a
> field.

Well, right now you can look at _columns, which should have most of the 
stuff you'd want.  Ideally the SQLMeta object (in this redesign) would 
have a clear set of methods for doing introspection.

For this case, I think it's better for the object to introspect itself, 
and that you add a method to it like .fields() or something.  Of course, 
you still need some form of introspection, even if the object is 
introspecting itself.

I think for joins, you are really thinking of ForeignKey (or maybe 
RelatedJoin, I suppose), where you want to find all the possible objects 
that this object could point to.  In this case I think you want to look 
at the ForeignKey object (which should be available through _columns), 
and do something like 
SQLObject.findClass(ForeignKeyColObj.foreignKey).search() to get the 
possible options.

   Ian