Hi
The solution is to use interfaces, but if you don't it would be
difficult to implement a factory pattern
There is this thing in OO language users which seems to be the muddy
area between scalars and objects,
ie is a TStringList a simple object or a complex scalar, of course it
doesn't help that Delphi garbage collects scalars
but not objects
Maybe i've been writing to much PHP
Neven
You guys don't consider a constructor a function then?
I think its totally stylistic, if you want to have functions returning
objects fine, just make it plain that they do,
IMHO
Neven
The downside to having "creator function"s returning objects is that you
have to duplicate the code in TObject.Create to ensure safety, as Struan
pointed out.
// Regular usage: constructor code guarantees no memory leak possibility
MyObject := TMyObject.Create;
try
...
finally
MyObject.Free;
end;
Replace TMyObject.Create with a creator function and you have to implement
its safety code again yourself:
// Function returning constructed object requires try/except to be safe
function CreateMyObject: TMyObject;
begin
...
Result := TMyObject.Create;
try
{
Any code you might put in here requires this encompassing try/except block
to prevent a memory leak occurring if an exception occurs
}
except
Result.Free;
raise;
end;
end;
And the same again for any additional levels of nesting. Not great from the
POV of encapsulation.
Cheers,
Carl
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