Here is most? of the code.
There are 2 areas to change (TReader & TStream). We have made it virtual so
that by default the normal TReader is used, hence the change to TStream, but
we also have the modified TReader (TReaderLocal) for the different
behaviour. We just had to change TReader to get at virtual methods for the
two different methods required
var
StreamReaderClass: TReaderClass = TReader; //This allows different
kinds of specialised TReaders to be used.
function TStream.ReadComponent(Instance: TComponent): TComponent;
var
Reader: TReader;
begin
// Reader := TReader.Create(Self, 4096);
Reader := StreamReaderClass.Create(Self, 4096);
try
Result := Reader.ReadRootComponent(Instance);
finally
Reader.Free;
end;
end;
{ TReaderLocal }
function TReaderLocal.FindInheritedNestedComponent(Root: TComponent; const
NamePath: string): TComponent;
begin
//
//The following piece of code is added for the special case of form
loading when cross linking
//across forms. First attempt to find the component reference in one of
the owners rather
//than relying on global references - and name changes.
//This is also matched by a change in TReader.ReadRootComponent //
FindUniqueName
//
if Assigned( Root.Owner ) then begin
Root := Root.Owner;
repeat
Result := FindNestedComponent( Root, NamePath);
if Assigned( Result ) then Exit;
Root := Root.Owner;
until not Assigned( Root );
end;
Result := nil;
end;
function TReaderLocal.FindUniqueName(const Name: string; Component:
TComponent): string;
var
I: Integer;
begin
//
//The default implementation of this ensures there are unique global names
for root components - eg TForm, TDataModule etc.
//This implementation does not care, as it assumes there are not really
any global components.
//Instead the name must just be unique in the component owners name space
instead - so that when we assign to Component.Name, no exception is raised.
//
//The code in FindInheritedNestedComponent relies on this, ie names not to
change. Unless they must.
//
//This is also matched by a change in TReader.DoFixupReferences
//
try
Component.Name := Name;
Result := Name;
except
on EComponentError do begin
//We haved detected a duplicate name, so find a unique name for this
component in it's owners name space
if Assigned( Component.Owner ) then begin
I := 1;
Result := Format('%s_%d', [Name, I]);
while Assigned( Component.Owner.FindComponent( Result )) do begin
Inc(I);
Result := Format('%s_%d', [Name, I]);
end;
end else raise;
end else raise;
end;
end;
procedure TReader.DoFixupReferences;
var
I: Integer;
CompName: string;
Reference: Pointer;
begin
if FFixups <> nil then
try
for I := 0 to FFixups.Count - 1 do
with TPropFixup(FFixups[I]) do
begin
CompName := FName;
ReferenceName(CompName);
Reference := FindNestedComponent(FInstanceRoot, CompName);
if not Assigned( Reference ) then Reference :=
FindInheritedNestedComponent( FInstanceRoot, CompName );
{ Free any preexisting global fixups for this instance/property.
Last fixup added is the only one that counts.
In particular, fixups created when streaming inherited
forms/frames
must be destroyed when overriding references are found later
in the stream. }
RemoveGlobalFixup(FFixups[I]);
if (Reference = nil) and MakeGlobalReference then
begin
GlobalFixupList.Add(FFixups[I]);
FFixups[I] := nil;
end
else
ResolveReference(Reference);
end;
finally
FreeFixups;
end;
end;
-----Original Message-----
From: Allan, Samuel [mailto:[EMAIL PROTECTED]
Sent: Monday, 8 December 2003 16:03
To: NZ Borland Developers Group - Delphi List
Subject: RE: [DUG] Form / DataModule Creation
Hi Myles,
To me, this sounds like the best solution other than what I've allready
done, because some of the InfoPower components (which we use quite a
lot) link directly to datasets, so even if we were to write our own
TDataSource descendant as Max suggests, we would then have to write our
own descendents for all the InfoPower stuff as well.
However, I know very little myself on how the streaming system works. I
have been reading up, but it would be very helpful if you could tell me
what to change, or send me your altered Classes.pas and I'll work it out
from there. Then I can more quickly gain understanding and put something
concrete to the people who make big decisions like this and let them
decide.
Thanks,
Samuel
-----Original Message-----
From: Myles Penlington [mailto:[EMAIL PROTECTED]
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