Pascal (Lazarus/Delphi)

Iterate JSON where Member Names are Data Values

See more JSON Examples

Demonstrates how to parse JSON where member names are not keywords, but instead are data values. 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;
  numMembers: Integer;
  i: Integer;
  name: string;
  jRecord: TJsonObject;

begin
  success := False;

  json := TJsonObject.Create;

  success := json.LoadFile('qa_data/json/valuesAsNames.json');

  //  Imagine we have JSON such as the following:

  //  {
  //    "1680": {
  //      "entity_id": "1680",
  //      "type_id": "simple",
  //      "sku": "123"
  //    },
  //    "1701": {
  //      "entity_id": "1701",
  //      "type_id": "simple",
  //      "sku": "456"
  //    }
  //  }
  //  

  //  This presents a parsing problem because the member names, such as "1680"
  //  are not keywords.  Instead they are data values.  We don't know what they
  //  may be in advance.  

  //  To solve, we iterate over the members, get the name of each, ...
  numMembers := json.Size;

  for i := 0 to numMembers - 1 do
    begin

      name := json.NameAt(i);

      WriteLn(name + ':');
      jRecord := json.ObjectAt(i);

      WriteLn('entity_id: ' + jRecord.StringOf('entity_id'));
      WriteLn('type_id: ' + jRecord.StringOf('type_id'));
      WriteLn('sku: ' + jRecord.StringOf('sku'));

      jRecord.Free;

    end;



  json.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.