unit uDAScriptingProvider;

{----------------------------------------------------------------------------}
{ Data Abstract Library - Core Library                                       }
{                                                                            }
{ compiler: Delphi 6 and up, Kylix 3 and up                                  }
{ platform: Win32, Linux                                                     }
{                                                                            }
{ (c)opyright RemObjects Software. all rights reserved.                      }
{                                                                            }
{ Using this code requires a valid license of the Data Abstract              }
{ which can be obtained at http://www.remobjects.com.                        }
{----------------------------------------------------------------------------}

{$I DataAbstract.inc}

interface

uses
  Classes, SysUtils;

type
  TScriptableComponent = class;
  TDAScriptingProvider = class(TComponent)
  private
    FScriptableComponent: TScriptableComponent;
    procedure SetScriptableComponent(const Value: TScriptableComponent);
  protected
    procedure Notification(AComponent: TComponent; Operation: TOperation); override;
  published
    property ScriptableComponent: TScriptableComponent read FScriptableComponent write SetScriptableComponent;
  end;

  IDAScriptingProvider = interface
  ['{6D19A2F9-233A-4EE6-95EC-CDFCD7410C15}']
  end;

  EDAScriptError = class(Exception);
  EDAScriptCompileError = class(EDAScriptError);

  TScriptableComponent = class(TComponent)
  private
    fScriptingProvider: TDAScriptingProvider;
    procedure SetScriptingProvider(const Value: TDAScriptingProvider);
  protected
    procedure Notification(AComponent: TComponent; Operation: TOperation); override;
  published
    property ScriptingProvider: TDAScriptingProvider read fScriptingProvider write SetScriptingProvider;
  end;



implementation

{ TScriptableComponent }

procedure TScriptableComponent.Notification(AComponent: TComponent;
  Operation: TOperation);
begin
  inherited;
  if (Operation = opRemove) then begin
    if (AComponent = fScriptingProvider) then fScriptingProvider := nil;
  end;
end;

procedure TScriptableComponent.SetScriptingProvider(const Value: TDAScriptingProvider);
begin
  if fScriptingProvider <> Value then begin
    if fScriptingProvider <> nil then fScriptingProvider.ScriptableComponent:=nil;
    if Value <> nil then Value.ScriptableComponent := Self;
    if Assigned(fScriptingProvider) then fScriptingProvider.FreeNotification(self);
  end;
end;

{ TDAScriptingProvider }

procedure TDAScriptingProvider.Notification(AComponent: TComponent;
  Operation: TOperation);
begin
  inherited;
  if (Operation = opRemove) then begin
    if (AComponent = FScriptableComponent) then FScriptableComponent := nil;
  end;
end;

procedure TDAScriptingProvider.SetScriptableComponent(
  const Value: TScriptableComponent);
begin
  if FScriptableComponent <> Value then begin
    if FScriptableComponent <> nil then begin
      FScriptableComponent.fScriptingProvider:=nil;
      FScriptableComponent.RemoveFreeNotification(Self);
    end;
    FScriptableComponent := Value;
    if Assigned(FScriptableComponent) then begin
      FScriptableComponent.fScriptingProvider := Self;
      FScriptableComponent.FreeNotification(Self);
    end;
  end;
end;

end.