How call the CreateOleObject function using dwscript? - delphi

Question

I'm trying to execute this code (this is a minimal sample in order to use CreateOleObject) from inside of a dwscript
function GetFileVersion(const FileName: string): string;
var
V : OleVariant;
begin
V := CreateOleObject('Scripting.FileSystemObject');
Result := V.GetFileVersion(FileName);
end;
So far i tried this
{$APPTYPE CONSOLE}
{$R *.res}
uses
SysUtils,
ComObj,
ActiveX,
dwsComp,
dwsCompiler,
dwsExprs,
dwsCoreExprs;
procedure Execute;
var
LScript: TDelphiWebScript;
LUnit: TdwsUnit;
LProg: IdwsProgram;
LExec: IdwsProgramExecution;
begin
LScript := TDelphiWebScript.Create(NIL);
LUnit := TdwsUnit.Create(NIL);
try
LUnit.UnitName := 'Foo';
LUnit.Script := LScript;
// compile a simple script
LProg := LScript.Compile(
'function GetFileVersion(const FileName: string): string;'+sLineBreak+
'var'+sLineBreak+
' V : Variant;'+sLineBreak+
'begin'+sLineBreak+
' V := CreateOleObject(''Scripting.FileSystemObject'');'+sLineBreak+
' Result := V.GetFileVersion(FileName);'+sLineBreak+
'end;'+sLineBreak+
''+sLineBreak+
'PrintLn(GetFileVersion(''Foo''));'+sLineBreak+
''
);
if LProg.Msgs.HasErrors then begin
Writeln(LProg.Msgs.AsInfo);
Exit;
end;
try
LExec := LProg.Execute;
except
on E: Exception do
WriteLn(E.Message + sLineBreak + LExec.Msgs.AsInfo );
end;
Writeln(LExec.Result.ToString);
finally
LScript.Free;
end;
end;
begin
try
Execute;
Readln;
except
on E: Exception do
Writeln(E.ClassName, ': ', E.Message);
end;
end.
But i'm getting this error message
Syntax Error: Unknown name "CreateOleObject" [line: 5, column: 8]
the question is how i can execute the CreateOleObject function using dwscript?
UPDATE
Following the Linas suggestions I could finally resolve the issue.
This is a sample working application
uses
SysUtils,
ComObj,
ActiveX,
dwsComp,
dwsCompiler,
dwsExprs,
dwsComConnector,
dwsCoreExprs;
procedure Execute;
var
LScript: TDelphiWebScript;
LUnit: TdwsUnit;
LProg: IdwsProgram;
LExec: IdwsProgramExecution;
LdwsComConnector : TdwsComConnector;
begin
LScript := TDelphiWebScript.Create(NIL);
LdwsComConnector:=TdwsComConnector.Create(nil);
LdwsComConnector.Script:=LScript;
LUnit := TdwsUnit.Create(NIL);
try
LUnit.UnitName := 'Foo';
LUnit.Script := LScript;
// compile a simple script
LProg := LScript.Compile(
'function GetFileVersion(const FileName: string): string;'+sLineBreak+
'var'+sLineBreak+
' V : OleVariant;'+sLineBreak+
'begin'+sLineBreak+
' V := CreateOleObject(''Scripting.FileSystemObject'');'+sLineBreak+
' Result := VarToStr(V.GetFileVersion(FileName));'+sLineBreak+
'end;'+sLineBreak+
''+sLineBreak+
'PrintLn(GetFileVersion(''C:\Bar\Foo.exe''));'+sLineBreak+
''
);
if LProg.Msgs.HasErrors then begin
Writeln(LProg.Msgs.AsInfo);
Exit;
end;
try
LExec := LProg.Execute;
except
on E: Exception do
WriteLn(E.Message + sLineBreak + LExec.Msgs.AsInfo );
end;
Writeln(LExec.Result.ToString);
finally
LScript.Free;
LdwsComConnector.Free;
end;
end;
begin
try
CoInitialize(nil);
try
Execute;
Readln;
finally
CoUninitialize;
end;
except
on E:Exception do
Writeln(E.Classname, ':', E.Message);
end;
end.

Answer 1

This can be accomplished in two ways.
1 way: You must drop TdwsComConnector (from unit dwsComConnector) to your data module or form (or create it manually) and assign your script instance to it. e.g.:
dwsComConnector1.Script := LScript;
2 way:
interface
uses
dwsFunctions, dwsSymbols, dwsExprs;
type
TCreateOleObjectFunc = class(TInternalFunction)
procedure Execute(info : TProgramInfo); override;
end;
implementation
uses
OleAuto;
{ TCreateOleObjectFunc }
procedure TCreateOleObjectFunc.Execute(info : TProgramInfo);
begin
Info.ResultAsVariant := CreateOleObject(Info.ValueAsString['ClassName']);
end;
initialization
RegisterInternalFunction(TCreateOleObjectFunc, 'CreateOleObject', ['ClassName', cString], cVariant, True);
This will expose CreateOleObject function to DWScript so you could use it.
Also you should declare your V as OleVariant instead of Variant and change the line to Result := VarToStr(V.GetFileVersion(FileName)); to make it work properly.