On Sat, 16 Oct 2010, Andrew Brunner wrote:
I've got a class factory problem I'm trying to resolve and it appears
I'm at a point where it's probably better to ask for help.
TCoreObjects=class;
TCoreObject=Class (TPersistent)
protected
class procedure VerifyIDs(var Module:TDBMSModule); Virtual; abstract;
end;
TAdminCore=Class(TCoreObject)
protected
class procedure VerifiyIDs(var Module:TDBMSModule); override;
end;
<SNIP>
procedure VerifyIDs(Var Module:TDBMSModule);
var
iLcv:integer;
ItemP:PCoreObjectItem; // Just record storing classname to load and
(each core object implment is loaded just not detailed here for
simplicity)
coGeneric:TPersistentClass;
coItem:TCoreObject;
begin
for iLcv:=0 to High(CoreObjectItems) do begin
ItemP:=CoreObjectItems[iLcv];
coGeneric:=GetClass(ItemP^.ClassName);
if (coGeneric<>nil) and coGeneric.InheritsFrom(TCoreObject) then begin
coItem:=coGeneric as TCoreObject << COMPILER ERROR :-(
Of course it errors, you're trying to store a VMT in an object instance.
You chould declare
TCoreObjectClass = Class (TCoreObject);
and
coItem : TCoreObjectClass;
Then
coItem:=TCoreObjectClass(coGeneric);
coItem.VerifyIDs(Module);
Should work. Untested (not enough code provided) but I think the above should
work.
Michael.
_______________________________________________
fpc-pascal maillist - fpc-pascal@lists.freepascal.org
http://lists.freepascal.org/mailman/listinfo/fpc-pascal
