Re: EAV (Re: Object-relational impedence)

On Sat, 29 Mar 2008 04:47:01 GMT, Brian Selzer wrote:

> There is a table for attributes that are common to all
> possible widgets, and a table for each set of attributes that are common not
> to all possible widgets, but rather to a subset of all possible widgets.

It is interesting to see people reinventing the wheel (class). The set of "all possible widgets having attributes T, U, V" is a class.

But that is not my point. The problem with widgets hierarchy is that there are three axes of widget relations. You were discussing only one of them attributes, which is usually directly mapped to types. This is not that big deal. More difficult are other two:

2. Visual containment. Widgets can consist of / contain other widgets.

3. Signal handing. Handlers of widget events are composed in a certain hierarchical way.

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de