Using the Result arg in SuperObject

Question

i'm using this superobject unit in one of my project as an rpc protocol, and inside a remote called procedure (signature has a var Result arg) i want to know how to use that arg...

isn't there a documentation ? thanks.

program test_rpc;

{$IFDEF FPC}
  {$MODE OBJFPC}{$H+}
{$ELSE}
  {$APPTYPE CONSOLE}
{$ENDIF}

uses
  SysUtils, superobject;

procedure controler_method1(const This, Params: ISuperObject; var Result: ISuperObject);
var
  i: Integer;
begin
  write('action called with params ');
  writeln(Params.AsString);

  try
    // How do i use Result arg to return a value ? as if it were a function returning string
    Result
  except
    exit;
  end;
end;

var
  s: ISuperObject;
begin
  s := TSuperObject.Create;
  s.M['controler.action1'] := @controler_method1;
  try
    s['controler.action1("HHAHAH")'];
  finally
    s := nil;
    writeln('Press enter ...');
    readln;
  end;
end.

Are you sure that you've given us enough information? It's not clear to me what this `Result` is that you talk of. Do you need to explain more? Are you talking about `TSuperMethod = procedure(const This, Params: ISuperObject; var Result: ISuperObject);`? And if so, what are you asking about it? — David Heffernan, Mar 03 '13 at 12:04
Whoops, looks like support forum at http://www.progdigy.com/forums/ is gone — Jan Doggen, Mar 03 '13 at 12:16
@DavidHeffernan lets say i called a function, how do i return a result ? — , Mar 03 '13 at 13:33
You need to edit the question to supply these details. You should give us some context, and perhaps some sample code. — David Heffernan, Mar 03 '13 at 13:34

David Heffernan · Accepted Answer · 2013-03-03T16:30:03.683

When controler_method1 is called, the var parameter Result is nil. To return something to the caller you need to assign to Result.

Result := TSuperObject.Create;

That's an empty super object. You can now populate it with whatever values you like in the normal way.

Here is a simple demonstration:

program test_rpc;

{$IFDEF FPC}
  {$MODE OBJFPC}{$H+}
{$ELSE}
  {$APPTYPE CONSOLE}
{$ENDIF}

uses
  SysUtils,
  superobject in 'superobject.pas';

procedure controler_method1(const This, Params: ISuperObject;
    var Result: ISuperObject);
begin
  Result := TSuperObject.Create('Foo');
end;

var
  s: ISuperObject;
begin
  s := TSuperObject.Create;
  s.M['controler.action1'] := controler_method1;
  Writeln(s['controler.action1("HHAHAH")'].AsString);
  Readln;
end.

Using the Result arg in SuperObject

1 Answers1