How to parse to TDateTime a date time returned from a JSON String in Delphi XE 10 [duplicate]

Question

I receive the following JSON from a request:

{
  "cdPlayer": 3,
  "nmPlayer": "Player Name",
  "dtCreate": "2016-08-24T22:53:31.687",
  "dtChange": null,
  "idStatus": true
 }

I would like to load convert dtCreate and dtChange to TDateTime. How to properly do this? There is no TJSONDateTime to cast the GetValue. Below is my current code where I'm casting it to a plain String.

procedure TfrmPrincipal.btnInfoClick(Sender: TObject);
var
  jsonRoot: TJSONObject;
  tokenRequest: TRESTRequest;
  tokenResponse: TRESTResponse;
  tokenClient: TRESTClient;
  tokenAutenticacao: TOAuth2Authenticator;
begin
  tokenClient := TRESTClient.Create(nil);
  tokenRequest := TRESTRequest.Create(nil);
  tokenResponse := TRESTResponse.Create(nil);
  tokenAutenticacao := TOAuth2Authenticator.Create(nil);
  try
    tokenRequest.Client := tokenClient;
    tokenRequest.Response := tokenResponse;
    tokenRequest.Method := TRESTRequestMethod.rmPUT;
    tokenClient.Authenticator := tokenAutenticacao;
    tokenAutenticacao.TokenType := TOAuth2TokenType.ttBEARER;
    tokenAutenticacao.AccessToken := 'token_string';
    tokenClient.BaseURL := 'http://host/url/method';
    tokenRequest.Execute;
    jsonRoot:= TJSONObject.ParseJSONValue(tokenResponse.JSONText) as TJSONObject;
    Memo1.Lines.Add('cdPlayer => ' + jsonRoot.GetValue('cdPlayer').Value);
    Memo1.Lines.Add('nmPlayer=> ' + jsonRoot.GetValue('nmPlayer').Value);
    Memo1.Lines.Add('dtCreate=> ' + jsonRoot.GetValue('dtCreate').Value);
    Memo1.Lines.Add('dtChange=> ' + jsonRoot.GetValue('dtChange').Value);
    Memo1.Lines.Add('idStatus=> ' + (jsonRoot.GetValue('idStatus') as TJSONBool).ToString);
  finally
    tokenAutenticacao.Free;
    tokenResponse.Free;
    tokenRequest.Free;
    tokenClient.Free;
  end;
end;

I'm using Delphi XE 10 Seatle. Thanks

EDIT

As far as the duplicate goes, I had no ideia that this Data format was ISO 8601. That's why I couldn't find the answer anywhere through Google. Maybe my question will help some others that, like me, didn't know as well.

Answer 1

I would extract each part of the date (year, month, day, hours, minutes, milliseconds) from that string, and encode a datetime value. It's easy because each part is always at the same position.

function JSONDate_To_Datetime(JSONDate: string): TDatetime;
var Year, Month, Day, Hour, Minute, Second, Millisecond: Word;
begin
  Year        := StrToInt(Copy(JSONDate, 1, 4));
  Month       := StrToInt(Copy(JSONDate, 6, 2));
  Day         := StrToInt(Copy(JSONDate, 9, 2));
  Hour        := StrToInt(Copy(JSONDate, 12, 2));
  Minute      := StrToInt(Copy(JSONDate, 15, 2));
  Second      := StrToInt(Copy(JSONDate, 18, 2));
  Millisecond := Round(StrToFloat(Copy(JSONDate, 19, 4)));

  Result := EncodeDateTime(Year, Month, Day, Hour, Minute, Second, Millisecond);
end;