Question

In the main unit I have defined a function that is then called by another form with the appropriate parameter:

unit Parser;
interface
uses
[...]

function SaveGridLayoutToReg(ASaveViewName: AnsiString): Integer;

type
TForm1 = class(TForm)
[...]
function SaveGridLayoutToReg(ASaveViewName: AnsiString): Integer;
end;

[...]

function TForm1.SaveGridLayoutToReg(ASaveViewName: AnsiString): Integer;
var
  AStoreKey: string;
  AOptions: TcxGridStorageOptions;
  LayoutRegistryKey: TRegistry;
begin
  AStoreKey := 'Software\KTRT\Stats';

  AOptions := [];
  cxGrid1TableView1.StoreToRegistry(AStoreKey, True, AOptions, ASaveViewName);

  LayoutRegistryKey.RootKey:= HKEY_CURRENT_USER;
  if LayoutRegistryKey.OpenKey(AStoreKey+'\'+ASaveViewName, false) then
    Result := 0
  else
    Result := -1;
end;

In the other form:

[...]
uses Parser;

procedure TForm3.Button1Click(Sender: TObject);
var
LayoutRegistryKey: TRegistry;
AStoreLocation : AnsiString;
AStoreKey: string;
begin
  AStoreLocation := Edit1.Text;
  if Parser.SaveGridLayoutToReg(AStoreLocation) <> 0 then
    Label1.Visible := True
  else
  begin
    Label1.Visible := False;
    Form3.Visible := False;
  end;
end;
[...]

I am somehow doing it wrong since I keep getting the error

Unsatisfied forward or external declaration

If I don’t declare the function in the TForm1 class then the grid view won’t be found. If I don’t declare the function after the “uses” clause, I won’t be able to call it from the other form.
I really can’t get it 🙁

Answer 1

You declare two functions in the interface section, namely, SaveGridLayoutToReg at

function SaveGridLayoutToReg(ASaveViewName: AnsiString): Integer;

and TForm1.SaveGridLayoutToReg a few lines later. But in the implementation section, you only implement the latter one.

That is, you need to replace

unit Parser;
interface
uses
[...]

function SaveGridLayoutToReg(ASaveViewName: AnsiString): Integer;

type
TForm1 = class(TForm)
[...]
function SaveGridLayoutToReg(ASaveViewName: AnsiString): Integer;
end;

with

unit Parser;
interface
uses
[...]

type
TForm1 = class(TForm)
[...]
function SaveGridLayoutToReg(ASaveViewName: AnsiString): Integer;
end;

or you have to implement both functions.