Binding an object with a TListView

I recently discovered Data Bindings, and followed this great tutorial about data binding and Delphi. I made it work with TEdit, but now I have a TObjectList and I achieved to bind them but it only works in one way. When I modify my TObjectList it changes the ListView, but when I modify the ListView : it won't change the TOBjectList.

Here's my code:

// When I change an Item of my ListView
procedure TForm1.ListView1Change(Sender: TObject; Item: TListItem;
  Change: TItemChange);
begin
  TBindings.Notify(Sender, 'Items.Item[' + IntToStr(Item.Index) +   '].Caption');
end;

// When I add a new item to my TListView, and I want that to be bound with my ListView
itemAdd := ListView1.Items.Add;
Item.Bind('id', ListView1, 'Items.Item[' + IntToStr(ListView1.Items.Count-1) + '].Caption');



  // The TBoundObject Class. Every class thatI want to bind with UI, inherits from this class
  unit U_TBoundObject;

  interface

  uses
    Generics.Collections, System.Bindings.Expression, System.Bindings.Helper;

  type
    TBoundObject = class
    protected
      type
        TExpressionList = TObjectList<TBindingExpression>;
    private
      FBindings: TExpressionList;
    protected
      procedure Notify(const APropertyName: string = '');
      property Bindings: TExpressionList read FBindings;
    public
      constructor Create; virtual;
      destructor Destroy; override;
      procedure Bind(const AProperty: string; const ABindToObject: TObject;
          const ABindToProperty: string; const ACreateOptions:
          TBindings.TCreateOptions = [coNotifyOutput, coEvaluate]);
      procedure ClearBindings;
    end;

  implementation

  constructor TBoundObject.Create;
  begin
    inherited;
    FBindings := TExpressionList.Create(false {AOwnsObjects});
  end;

  destructor TBoundObject.Destroy;
  begin
    ClearBindings;
    FBindings.Free;
    inherited;
  end;

  procedure TBoundObject.ClearBindings;
  var
    i: TBindingExpression;
  begin
    for i in FBindings do
      TBindings.RemoveBinding(i);
    FBindings.Clear;
  end;

  procedure TBoundObject.Notify(const APropertyName: string);
  begin
    TBindings.Notify(Self, APropertyName);
  end;

  procedure TBoundObject.Bind(const AProperty: string;
    const ABindToObject: TObject; const ABindToProperty: string;
    const ACreateOptions: TBindings.TCreateOptions);
  begin
    // From source to dest
    FBindings.Add(TBindings.CreateManagedBinding(
        { inputs }
        [TBindings.CreateAssociationScope([Associate(Self, 'src')])],
        'src.' + AProperty,
        { outputs }
        [TBindings.CreateAssociationScope([Associate(ABindToObject, 'dst')])],
        'dst.' + ABindToProperty,
        nil, nil, ACreateOptions));
    // From dest to source
    FBindings.Add(TBindings.CreateManagedBinding(
        { inputs }
        [TBindings.CreateAssociationScope([Associate(ABindToObject, 'src')])],
        'src.' + ABindToProperty,
        { outputs }
        [TBindings.CreateAssociationScope([Associate(Self, 'dst')])],
        'dst.' + AProperty,
        nil, nil, ACreateOptions));
  end;

  end.

I know what you are trying to do, but you are not really doing it.

Essentially, you are trying to bind the properties of two objects, but you are treating a subproperty (a property of a property) as if it were a property. You say it works one way round, but for me it didn't.

By handling the objects directly (rather than indirectly) it becomes much easier.

This is how I added and associated the objects in question

procedure TForm2.SpeedButtonAddClick(Sender: TObject);
var
  ItemAdd : TListItem;
  Item : TFeature;
begin
  Item := TFeature.Create;
  fObjectList.Add( Item );
  ItemAdd := ListView1.Items.Add;
  Item.Bind('id', ItemAdd, 'Caption');
end;

This is the code for object change

procedure TFeature.SetID(const Value: string);
begin
  if fID <> Value then // prevent an infinite loop
  begin
    fID := Value;
    TBindings.Notify( self, 'id' );
  end;
end;

(The test is to prevent the two objects continually updating each other)

And this is the code for ItemView change

procedure TForm2.ListView1Change(Sender: TObject; Item: TListItem;
  Change: TItemChange);
begin
  TBindings.Notify(Item, 'Caption');
end;

I have tested it and it works in both directions.