Pascal (Lazarus/Delphi)

Swap JSON Objects

See more JSON Examples

Demonstrates how to swap two JSON objects within a JSON document. Pascal (Lazarus/Delphi)

program ChilkatDemo;

// Demonstrates using the Chilkat Pascal wrapper via the C bridge DLL.
// Builds as a console application under Lazarus (FPC) or Delphi.

{$IFDEF FPC}
  {$MODE DELPHI}
{$ENDIF}
{$APPTYPE CONSOLE}

uses
  {$IFDEF UNIX}
  cthreads,
  {$ENDIF}
  SysUtils,
  CkDllLoader,
  Chilkat.JsonObject;

// ---------------------------------------------------------------------------

procedure RunDemo;
var
  success: Boolean;
  json: TJsonObject;
  index1: Integer;
  index2: Integer;
  jsonSara: TJsonObject;

begin
  success := False;

  json := TJsonObject.Create;
  json.EmitCompact := False;

  //  Load the following JSON:

  //  {
  //    "petter": {
  //      "DOB": "26/02/1986",
  //      "gender": "male",
  //      "country": "US"
  //    },
  //    "Sara": {
  //      "DOB": "13/05/1982",
  //      "gender": "female",
  //      "country": "FR"
  //    },
  //    "Jon": {
  //      "DOB": "19/03/1984",
  //      "gender": "male",
  //      "country": "UK"
  //    }
  //  }

  success := json.LoadFile('qa_data/json/people.json');
  if (success = False) then
    begin
      WriteLn(json.LastErrorText);
      Exit;
    end;

  //  Swap the positions of Jon and Sara.
  index1 := json.IndexOf('Jon');
  index2 := json.IndexOf('Sara');
  json.Swap(index1,index2);

  //  We have this now:
  WriteLn(json.Emit());

  //  {
  //    "petter": {
  //      "DOB": "26/02/1986",
  //      "gender": "male",
  //      "country": "US"
  //    },
  //    "Jon": {
  //      "DOB": "19/03/1984",
  //      "gender": "male",
  //      "country": "UK"
  //    },
  //    "Sara": {
  //      "DOB": "13/05/1982",
  //      "gender": "female",
  //      "country": "FR"
  //    }
  //  }

  //  To swap an inner member:

  jsonSara := TJsonObject.Create;
  json.ObjectOf2('Sara',jsonSara);

  index1 := jsonSara.IndexOf('DOB');
  index2 := jsonSara.IndexOf('country');
  jsonSara.Swap(index1,index2);

  //  We now have this:
  WriteLn(json.Emit());

  //  {
  //    "petter": {
  //      "DOB": "26/02/1986",
  //      "gender": "male",
  //      "country": "US"
  //    },
  //    "Jon": {
  //      "DOB": "19/03/1984",
  //      "gender": "male",
  //      "country": "UK"
  //    },
  //    "Sara": {
  //      "country": "FR",
  //      "gender": "female",
  //      "DOB": "13/05/1982"
  //    }
  //  }


  json.Free;
  jsonSara.Free;

end;

// ---------------------------------------------------------------------------

begin

  try
    RunDemo;
  except
    on E: Exception do
      WriteLn('Unhandled exception: ', E.ClassName, ': ', E.Message);
  end;

  WriteLn;
  {$IFDEF MSWINDOWS}
  WriteLn('Press Enter to exit...');
  ReadLn;
  {$ENDIF}
end.