Hi !

> Hi Sergio,
> 
> 
> > I've add a new type of filter to dbforms's capability, an sql filter 
> > that is simply an SQL condition, passed as a DbFormTag's attribute. This
> > type of filter is much better than the old one, but the coding changes 
> > are rilevant, so I post here the diff, and we can discuss about it pros 
> > and cons and decide what to do. In bookstore examples there is an 
> > application of filtering, in master and child forms.
> 
> Good idea, but i would prefer a backward compatible mode. I think a new
> attribute like SQLFilter would be better solution. I think there are lot of
> applications outside the world wich work with the old filter and where 
attributes
> and i do not like to break the compatiblity.

Ok, I must say currently I'm not working with DBForms code so I don't have the 
focus on the whole thing... anyway...
I think that there should be only one mode to make a thing. But in this 
manner... compatibility will be broken. I suppose it's not a good idea try to 
implement a factory / strategy pattern only to incapsulate a filter 
functionality ... too complex to do, IMHO.

Usually I prefer to specify "conditions" using SQL statements... you can have 
the most complex statement and then pass that damned string directly to the 
rdbms engine, without spending hours to debug a new "condition-meta-language".

The problem is that DbForms original engine is built around this concept - it 
uses a "cumulation of rules" to build a final SQL statement. Ah, yes, you 
know ;^) 

Anyway, I saw the development trend is to improve the project trying also to 
*simplify / refactoring*  the code where possible. Making UML diagrams I saw 
the new event handler is (am I right ?) simpler than the previous one.
Events code is simpler and uses standard patterns (DAO).
And I hope that there will ONLY one navigation system (the new one), not two.

So I think another step could be to use standard SQL to specify "all type of 
filters". Having only whereClause and orderBy attributes could be the best 
thing to obtain. 
Having another (redundant) attribute is not a good idea, IMHO.

Luca




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