References:
> QSG code example provided with the installer

After installation, a group PyBridge will appear in the Tool Palette of Delphi, where you can find the new component  TPBFileStorage

New component TPBFileStorage can be found in the Tool Palette under PyBridge group

Place  TPBFileStorage on the form and set up its main properties:

• FileName – full path to the storage file
• Name – name of the storage file

Now PBFileStorage is ready to be used. A file storage file is an object that has a familiar tree structure similar to a file system in which files and variables of various types can be placed. To demonstrate how it works, let’s create a very simple application with main component functions. Add buttons as displayed below. Add one Memo field for displaying status messages about the execution of the called functions. Add another Memo field for displaying the tree structure of the storage file.

Application layout to demonstrate basic PBFileStorage functions

First, it is necessary to initialize the work with FileStorage with the OPEN command. In this case, we either create a new file or open an existing file:

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procedure TFileStorageDemo.OpenButtonClick(Sender: TObject);
begin
  PBFileStorage1.OpenStorage;
end;

To display the result of initializing the storage file, create an OnOpen event handler:

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procedure TFileStorageDemo.PBFileStorage1Open(const AFileName: string);
begin
  Memo1.Lines.Add('File ' + AFileName + ' is Opened');
  if PBFileStorage1.FileIsStorage then
    Memo1.Lines.Add('File Is a Storage')
  else
    Memo1.Lines.Add('File Is not a Storage');
  DrawTree;
end;

Events list of PBFileStorage object

Press “Open” to open a storage file and display it’s tree structure

In the “Create dir” button click event handler, create two directories:

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procedure TFileStorageDemo.Create_dirButtonClick(Sender: TObject);
begin
  if PBFileStorage1.CreateDirectory('a\b\c') then
    Memo1.Lines.Add('CreateDirectory - OK')
  else
    Memo1.Lines.Add('CreateDirectory - FALSE');

  if PBFileStorage1.CreateDirectory('d\e') then
    Memo1.Lines.Add('CreateDirectory - OK')
  else
    Memo1.Lines.Add('CreateDirectory - FALSE');
end;

To display the result of creating directories, create an OnCreateDirectory event handler:

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procedure TFileStorageDemo.PBFileStorage1CreateDirectory(const APath: string);
begin
  Memo1.Lines.Add('Directory ' + APath + ' is created');
  DrawTree;
end;

Press “Create dir” to create two directories and update a tree structure

In the “Write” button click event handler, create a variable and save its value in the file space of our storage file in the form of the file “test” in the “d\e” directory created earlier:

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procedure TFileStorageDemo.WriteButtonClick(Sender: TObject);
var
  st: integer;
begin
  st := 125;
  if PBFileStorage1.Write('d\e\test', st) then
    begin
      Memo1.Lines.Add('Write - OK');
      Memo1.Lines.Add(Inttostr(st));
    end
  else
    Memo1.Lines.Add('Write - FALSE');
end;

To display the result of writing a value to a variable, create an OnWrite event handler.

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procedure TFileStorageDemo.PBFileStorage1Write(const APath, ADataType: string);
begin
  Memo1.Lines.Add('Write ' + APath + ' (' + ADataType + ')');
  DrawTree;
end;

Press “Write” to write a “test” file and update a tree structure

In “Read” button click event handler, we will try to read the value of the previously created variable from the file “test” from the directory “a\b\c” (the file “test” is in the directory “d\e”):

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procedure TFileStorageDemo.ReadButtonClick(Sender: TObject);
var
  st: integer;
begin
  if PBFileStorage1.Read('a\b\c\test', st) then
    begin
      Memo1.Lines.Add('Read - OK');
      Memo1.Lines.Add(inttostr(st));
    end
  else
    Memo1.Lines.Add('Read - FALSE');
end;

To display the reading result, create an OnRead event handler:

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procedure TFileStorageDemo.PBFileStorage1Read(const APath, ADataType: string);
begin
  Memo1.Lines.Add('Read ' + APath + ' (' + ADataType + ')');
end;

When you press the “Read” button, a message appears stating that it was not possible to read the value

Let’s use the “Move” function to move the file “test” from the directory “d\e” to the directory “a\b\c”:

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procedure TFileStorageDemo.MoveButtonClick(Sender: TObject);
begin
  PBFileStorage1.Move('d\e\test', 'a\b\c\');
end;

To display the result of the move, create an OnMove event handler:

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procedure TFileStorageDemo.PBFileStorage1Move(SrcPath, DstPath: string);
begin
  Memo1.Lines.Add('Move ' + SrcPath + ' in ' + DstPath);
  DrawTree;
end;

Press “Move” to move “test” file to the “a\b\c” folder . Press “Read” to display the stored value “Hello World”

Let’s use the “Copy” function to copy the file “test” from the directory “a\b\c” to the directory “d\e”:

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procedure TFileStorageDemo.CopyButtonClick(Sender: TObject);
begin
  PBFileStorage1.Copy('a\b\c\test', 'd\e\');
end;

To represent the move results, create an OnCopy event handler:

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procedure TFileStorageDemo.PBFileStorage1Copy(SrcPath, DstPath: string);
begin
  Memo1.Lines.Add('Copy ' + SrcPath + ' in ' + DstPath);
  DrawTree;
end;

Press “Copy” to copy “test” file to the folder «d\e\»

In the “Find” button click event handler, create a search procedure by the name of the file “test”:

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procedure TFileStorageDemo.FindButtonClick(Sender: TObject);
var
  objlist: TStringArray;
  i, cnt: Integer;
begin
  objlist := PBFileStorage1.Find('test');
  cnt := Length(objlist);
  if cnt > 0 then
  begin
    for i := 0 to Pred(cnt) do
    begin
      Memo1.Lines.Add(objlist[i]);
    end;
  end;
end;

Press “Find” to find “TestString” file in the folders: «a\b\c» and «d\e\»

In the “Delete” button click event handler, create a procedure for deleting the subdirectory “b” from the directory “a” and the subdirectory “e” from the directory “d”:

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procedure TFileStorageDemo.DeleteButtonClick(Sender: TObject);
begin
  if PBFileStorage1.Delete('a\b') then
    Memo1.Lines.Add('Delete - OK')
  else
    Memo1.Lines.Add('Delete - FALSE');

  if PBFileStorage1.Delete('d\e') then
    Memo1.Lines.Add('Delete - OK')
  else
    Memo1.Lines.Add('Delete - FALSE');
end;

To display the result of deletion, create an OnDelete event handler:

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procedure TFileStorageDemo.PBFileStorage1Delete(const APath: string);
begin
  Memo1.Lines.Add(APath + ' is deleted');
  DrawTree;
end;

Press “Delete” to delete subdirectories

In the “Save” button click event handler, create a procedure for saving the storage file:

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procedure TFileStorageDemo.SaveButtonClick(Sender: TObject);
begin
  PBFileStorage1.SaveStorage;
end;

To present the results of the save, create an OnSave event handler:

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procedure TFileStorageDemo.PBFileStorage1Save(const AFileName: string);
begin
  Memo1.Lines.Add(AFileName + ' is saved');
end;

Press “Save” to save the storage file

When the “Close” command is executed, the current state of the storage file is saved and access to it is closed. To resume work with the file, you need to open it again.

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procedure TFileStorageDemo.CloseButtonClick(Sender: TObject);
begin
  PBFileStorage1.CloseStorage;
end;

Press “Close” to close the storage file

This example demonstrates how you can easily and quickly create and modify a tree-structured storage file with a help of PBFileStorage component. Now you can also enjoy the full power of PBFileStorage in your applications!