Joao Morais

(portuguese)

From my point of view, one thing that is really missing for Delphi/Lazarus is a better application’s form management. Two problems: an independent public variable is used to control an instance, and the ‘please place everything within the form’ approach. The first one requires the programmer to either create the form at the start of the application and not destroy it anymore, or it requires the programmer to create the forms and keep track of object destruction insuring that no variable points to a destroyed object. The second, among other problems, requires that the first one works perfectly so that the communication between forms can work. Continue Reading »

(portuguese)

Contrary to some object oriented programming gurus, I was not much into interfaces. The first uses were under utilized, as just a memory manager assistant (interfaces in object pascal have reference counting maintained by the compiler, contrary to classes). Continue Reading »

(portuguese)

A few years ago, just after I learned about object oriented data types, I also learned about some things that some people hate about using OO to manipulate data for object persistence (storage for future retrieval). Most of the blame is on the OPF. Continue Reading »

(portuguese)

(special thanks to Richard Scoop)

I have encountered, both in newgroups and mailinglists, some discussions about Object Oriented Models vs Relational Models. This post tries to describe some problems and the solutions of both approaches for a programmer’s day to day work. Continue Reading »

(portuguese)

(special thanks to Richard Scoop)

What do Object Persistence Framework (OPF) and its brother Model-View-Presenter (MVP) have in common, other than being object oriented patterns? Both use the same source of data. At one end the OPF reads information from a persistence mechanism (eg a RDBMS) and at the other end the MVP presents the information that the user sees from it. The link between these two is what a few authors call a Value Type Framework, which I call Data Type Framework or simply the Subject Framework. Continue Reading »