[fpc-devel] property cam access private symbol from class in other unit
lazarus at mfriebe.de
Wed Jan 4 21:10:09 CET 2012
On 04/01/2012 20:01, Pete Cervasio wrote:
> On Wednesday, January 04, 2012 01:26:52 pm Martin wrote:
> > TForm1 = class(TForm)
> > public
> > FFoo: TFoo;
> > property Num: Integer read FFoo.FBar;
> > end;
> Just a 'for your info' note: Kylix doesn't allow the above. Nor does
> it allow accessing the property FFoo.Bar as a parameter to the read.
> This makes sense to me, though, because FFoo may very well be nil when
> code tries to read Form1.Num.
Well the property is rejected by fpc too. But then a property is always
treated as if it was a function (or procedure for the setter). So that
is more than referring to a field.
To be honest I discovered this by accident, it was meant to use a field
from a record...
the nil situation is not a concern here, a programmer can always write
code that can fail on nil pointers. FFoo could well have the same live
time as the Form...
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