Delphi FMX: Saving and loading container children - delphi

Question

Starting from this layout at design time.
(It contains several TLayout, TGridPanelLayout, TText elements as example)
At runtime, I am saving the complete objects structure to a file using ObjectBinaryToText
But when loading the file back from the file using ObjectTextToBinary, I get this result
Why the sub-controls are not taking the exqct same layout as saved before?
The file structure seems to be OK and containing all sub-controls as described when saving my form with the IDE
Here is a piece of code demonstrating the problem.
PAS File
unit Unit1;
interface
uses
System.SysUtils, System.Types, System.UITypes, System.Classes,
system.Variants, FMX.Types, FMX.Controls, FMX.Forms, FMX.Graphics,
FMX.Dialogs, FMX.Objects, FMX.Layouts, FMX.Controls.Presentation,
FMX.StdCtrls;
type
TForm1 = class(TForm)
RecTop: TRectangle;
ButtonSave: TButton;
ButtonClear: TButton;
ButtonLoad: TButton;
Layout1: TLayout;
GridPanelLayout1: TGridPanelLayout;
Text1: TText;
Text2: TText;
Text3: TText;
Text4: TText;
procedure ButtonSaveClick(Sender: TObject);
procedure ButtonClearClick(Sender: TObject);
procedure ButtonLoadClick(Sender: TObject);
procedure FormCreate(Sender: TObject);
private
{ Private declarations }
AppPath: string;
AppDatFile: String;
public
{ Public declarations }
end;
var
Form1: TForm1;
implementation
{$R *.fmx}
uses
System.IOUtils;
procedure TForm1.ButtonSaveClick(Sender: TObject);
var
FileStream : TFileStream;
MemStream : TMemoryStream;
begin
FileStream := TFileStream.Create(AppDatFile, fmCreate);
try
MemStream := TMemoryStream.Create;
MemStream.WriteComponent(Layout1);
MemStream.Position := 0;
ObjectBinaryToText(MemStream, FileStream);
finally
MemStream.Free;
FileStream.Free;
end;
end;
procedure TForm1.ButtonClearClick(Sender: TObject);
var
i: Integer;
begin
for i := pred(Layout1.ChildrenCount) downto 0 do
Layout1.Children[i].Free;
end;
procedure TForm1.ButtonLoadClick(Sender: TObject);
var
FileStream : TFileStream;
MemStream : TMemoryStream;
begin
if FileExists(AppDatFile) then
begin
FileStream := TFileStream.Create(AppDatFile, fmOpenRead);
try
MemStream := TMemoryStream.Create;
ObjectTextToBinary(FileStream, MemStream);
MemStream.Position := 0;
MemStream.ReadComponent(Layout1);
Layout1.Align:= TAlignLayout.Client;
finally
MemStream.Free;
FileStream.Free;
end;
end;
end;
procedure TForm1.FormCreate(Sender: TObject);
begin
AppPath:= TPath.GetLibraryPath;
AppDatFile:= TPath.Combine(AppPath, 'SaveLoadLayout.dat');
end;
end
FMX File
object Form1: TForm1
Left = 0
Top = 0
Caption = 'Form1'
ClientHeight = 480
ClientWidth = 640
FormFactor.Width = 320
FormFactor.Height = 480
FormFactor.Devices = [Desktop]
OnCreate = FormCreate
DesignerMasterStyle = 0
object RecTop: TRectangle
Align = Top
Size.Width = 640.000000000000000000
Size.Height = 41.000000000000000000
Size.PlatformDefault = False
end
object ButtonSave: TButton
Position.X = 8.000000000000000000
Position.Y = 8.000000000000000000
TabOrder = 3
Text = 'Save'
OnClick = ButtonSaveClick
end
object ButtonClear: TButton
Position.X = 96.000000000000000000
Position.Y = 8.000000000000000000
TabOrder = 2
Text = 'Clear'
OnClick = ButtonClearClick
end
object ButtonLoad: TButton
Position.X = 184.000000000000000000
Position.Y = 8.000000000000000000
TabOrder = 1
Text = 'Load'
OnClick = ButtonLoadClick
end
object Layout1: TLayout
Align = Client
Size.Width = 640.000000000000000000
Size.Height = 439.000000000000000000
Size.PlatformDefault = False
TabOrder = 4
object GridPanelLayout1: TGridPanelLayout
Align = Client
Size.Width = 640.000000000000000000
Size.Height = 439.000000000000000000
Size.PlatformDefault = False
TabOrder = 0
ColumnCollection = <
item
Value = 50.000000000000000000
end
item
Value = 50.000000000000000000
end>
ControlCollection = <
item
Column = 0
Control = Text1
Row = 0
end
item
Column = 1
Control = Text2
Row = 0
end
item
Column = 0
Control = Text3
Row = 1
end
item
Column = 1
Control = Text4
Row = 1
end>
RowCollection = <
item
Value = 50.000000000000000000
end
item
Value = 50.000000000000000000
end>
object Text1: TText
Align = Client
Size.Width = 320.000000000000000000
Size.Height = 219.500000000000000000
Size.PlatformDefault = False
Text = 'Text1'
end
object Text2: TText
Align = Client
Size.Width = 320.000000000000000000
Size.Height = 219.500000000000000000
Size.PlatformDefault = False
Text = 'Text2'
end
object Text3: TText
Align = Client
Size.Width = 320.000000000000000000
Size.Height = 219.500000000000000000
Size.PlatformDefault = False
Text = 'Text3'
end
object Text4: TText
Align = Client
Size.Width = 320.000000000000000000
Size.Height = 219.500000000000000000
Size.PlatformDefault = False
Text = 'Text4'
end
end
end
end

Answer 1

As I said in my comment, the problem is that WriteComponent wrongly write items with the format:
Control = Form1.Text1
This is not correct, it should be
Control = Text1
The behavior is maybe caused by the fact that serializing a component using other component, their owner is saved along.
The workaround is to correct what WriteComponent write. A simple implementation using a simple ReplaceString is like this:
procedure TForm1.ButtonSaveClick(Sender: TObject);
var
StringStream : TStringStream;
MemStream : TMemoryStream;
Buf : String;
begin
MemStream := nil;
StringStream := TStringStream.Create;
try
MemStream := TMemoryStream.Create;
MemStream.WriteComponent(Layout1);
MemStream.Position := 0;
ObjectBinaryToText(MemStream, StringStream);
Buf := StringReplace(StringStream.DataString,
' Control = ' + Self.Name + '.',
' Control = ', [rfReplaceAll]);
TFile.WriteAllText(AppDatFile, Buf);
finally
MemStream.Free;
StringStream.Free;
end;
end;
Be aware that this workaround implementation works for your example but could be confused because the search and replace do not use a real parser and could replace something else having the same form (A string property for example).