[fpc-devel] GetPropList and order of properties returned

[Graeme Geldenhuys]

Hi,

What are the rules regarding the order of a unsorted list of published 
properties using the GetPropList method, when inheritance has been used.
I had unit tests from a Delphi app that detected this difference.

Below is the results from Delphi and FPC.  The first set has been 
compiled with Delphi 7 and the second set of results from a exectable 
compiled with FPC 2.0.1

As you can see, Delphi lists the properties from the root object out, 
and FPC lists them from the outer object in.  Which one is doing it 
correctly, or is there no set rule?


[Delphi 7]
C:\Programming\Tests\GetPropList\D7_2>Project1.exe
Total property Count: 4
Property 1: Caption
Property 2: IntProp
Property 3: StrProp
Property 4: AnotherStrProp
---------------

[FPC 2.0.1]
C:\Programming\Tests\GetPropList\D7_2>Project1.exe
Total property Count: 4
Property 1: AnotherStrProp
Property 2: IntProp
Property 3: StrProp
Property 4: Caption
---------------


Here is the full source of the application
-------------------------------------------------
program project1;

{$IFDEF FPC}
   {$mode objfpc}{$H+}
{$ELSE}
   {$APPTYPE CONSOLE}
{$ENDIF}

uses
   SysUtils,
   TypInfo,
   Classes;

type
   TAObject = class(TPersistent)
   private
     FCaption: string;
   published
     property Caption: string read FCaption write FCaption;
   end;

   TBObject = class(TAObject)
   private
     FIntProp: Integer;
     FStrProp: String;
   published
     property IntProp: Integer read FIntProp write FIntProp;
     property StrProp: String read FStrProp write FStrProp;
   end;


   TCObject = class(TBObject)
   private
      FAStrProp: String;
   published
     property AnotherStrProp: String read FAStrProp write FAStrProp;
   end;

procedure ShowProperties;
var
   Obj: TCObject;
   i: Longint;
   lPropFilter: TTypeKinds;
   lCount: Longint;
   lSize: Integer;
   lList: PPropList;
begin
   Obj := TCObject.Create;
   lPropFilter := [tkInteger, tkLString {$ifdef FPC}, tkAString{$endif}];

   lCount  := GetPropList(Obj.ClassInfo, lPropFilter, nil, false);
   lSize   := lCount * SizeOf(Pointer);
   GetMem(lList, lSize);

   Writeln('Total property Count: ' + IntToStr(lCount));
   lCount := GetPropList(Obj.ClassInfo, lPropFilter, lList, false);
   for i := 0 to lCount-1 do
   begin
     Writeln('Property '+IntToStr(i+1)+': ' + lList^[i]^.Name);
   end;

   FreeMem(lList);
   Obj.Free;
   Writeln('---------------');
end;


begin
   ShowProperties;
end.

-------------------------------------------------

I'm running FPC 2.0.1 that came with Lazarus 0.9.10 on Windows 2000.

Regards,
   - Graeme -