[Lazarus] Exception dialog

[Michael Van Canneyt]

On Tue, 17 Mar 2009, Martin Friebe wrote:

> Graeme Geldenhuys wrote:
> > Please note, I don't use db-aware components, but here follows the
> > help from Kylix 3.
> >
> > On Tue, Mar 17, 2009 at 3:46 PM, Martin Friebe <lazarus at mfriebe.de> wrote:
> >   
> >> I have to admit, I have limited knowledge of the exact details of the
> >> data-aware components, and rather was making a general case about my
> >> perception of proper exception use.
> >> I just googled  => can you point me to some documentation on it?
> >>
> >> Following you description, I have no problem if an OnValidate allows the
> >> code to use an exception to signal the component some-error state.
> >> IMHO the component should have a well defined behaviour on getting this
> >> exception.
> >>     
> >
> >
> > ==========[ Kylix 3 help ]================
> > OnValidate event (TField)
> > -------------------------
> > Occurs just before the data is written to the record buffer.
> >   
> .....
> > To reject the current value of the field from the OnValidate event
> > handler, raise an exception.
> >
> >   
> Then to me the Delphi/Kylix implementation is flawed. Because it forces 
> me to do TWO things, even if I want to do only one of them.
> There should be:
> - an ExceptionClass TDataValitaionException (or whatever) which can be 
> used to abort writing the data, but not defer error handling to the mainloop
> - any other exception, that aborts the write, and transfers error 
> handling to the main loop
> 
> There are usages for both scenarios, so they should both be possible.

This may be so, but given the implementation as it is in Delphi, 
hopefully you can now understand my problem with the Lazarus
exception dialog :-)

Michael.