On 1/13/07, Al Boldi <[EMAIL PROTECTED]> wrote:
If you are verse in OOP, there is really no need for an OPF, as an OPF only
aids you in plumbing up your classes, while limiting you to the extent of
the specific BusinessObject.
I think you are missing the point of a OPF framework completely! The
OPF framework is there to persist (save) you objects to permanent
storage. Be that a text file (XML, CSV, TAB, etc) or a relational
database (Firebird, Oracle, DB2, etc). And if the OPF framework is
design correctly (as in the case of tiOPF) you can change the back-end
database even at runtime and nothing else needs to change in your
business objects or application. One of the demos in tiOPF is where
you load data from a CSV file, change the backend persistence layer
while the app is running and then save the data again, but this time
into a Firebird DB. All with 3 lines of code.
You should be able to say APerson.Save and not care how it gets saved,
but knowing that it has been done.
The tiOPF base classes also do not limit you in any way regarding your
Business Object design. For example the tiOPF framework doesn't use
Interfaces at all. I wanted that, so created my own
TInterfacedTIObject descending from the tiOPF's base TtiObject class.
This helped me implement Event Listeners like Java does. I implemented
the Observer pattern based on Interfaces instead of Objects.
Also an OPF normally has some really useful helper functions you can
use. In the case of tiOPF, have a look in Core/tiUtils.pas or
GUI/tiGUIUtils.pas
I'm not done converting the documentation to fpdoc format, but the
full documentation is in the .pas units. Have a look at:
http://opensoft.homeip.net/tiopf/core/tiutils/index-5.html
I would rather see some work put into a powerful Class-Editor, inlined into
InstantObjects is know for there GUI class editors, but the
InstantObjects framework has other limitations I cannot live with,
where tiOPF doesn't have that problem. I have thought of creating GUI
class editors for Lazarus and the tiOPF framework but decided it
wasn't needed. I have an extensive set of "code templates" in Lazarus
which allows me to build my business objects in seconds.
For example.
I type: poa <and press Ctrl-J>
and get a complete class layout. I have the same for the
implementation section of my classes and for my SQL visitors. By the
way, poa stands for "Persistent Object Abstract" :-)
the IDE, while being able to import/export UML.
I spoke to someone at the end of last year in this mailing list or in
the fpc-pascal mailing list (can't remember), where they started UML
support in Lazaras. Exporting UML from code, etc..
--
Graeme Geldenhuys
There's no place like S34° 03.168' E018° 49.342'
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