Remove Pair from TJsonObject-CodePudding

{
  "Test":{
    "A":{
      "ins":{
        "type":"pac",
        "id":{
          "values":{
            "test_number":"156764589",
            "val":"abcde",
            "val_2":"gggg",
            "val_3":"jjjj"
          },
          "verif":{
          },
          "bool":"INSTR"
        }
      }
    },
    "resp":{
      "image":"include"
    },
    "op":{
      "id":{
        "meth":"def"
      }
    }
  }
}

I am logging a http request been sent & need to remove an element from a TJsonObject for privacy. However when I attempt to remove key and log it still persists

TJSONObject *obj = (TJSONObject*) TJSONObject::ParseJSONValue(TEncoding::UTF8->GetString(id_http_wrap.msg));
obj->RemovePair("Test.A.ins.type.id.values.test_number");

CodePudding user response：

This should do the trick:

implementation

uses
  System.IOUtils, System.JSON;

procedure DoSomeJSONStuff;
var
  jsonstr: string;
  jo, jochild: TJSONObject;
begin
  jsonstr := TFile.ReadAllText('C:\Temp\example.json', TEncoding.UTF8);
  jo := TJSONObject.ParseJSONValue(jsonstr) as TJSONObject;
  if (jo <> nil) then begin
    try
      jochild := ((((jo.GetValue('Test') as TJSONObject).GetValue('A') as TJSONObject).GetValue('ins') as TJSONObject).GetValue('id') as TJSONObject).GetValue('values') as TJSONObject;
      jochild.RemovePair('test_number');
      TFile.WriteAllText('C:\Temp\example_changed.json', jo.ToString, TEncoding.UTF8);
    finally
      jo.Free;
    end;
  end;
end;

Keep in mind, that TFile.ReadAllText and WriteAllText with UTF-8 encoding is actually UTF-8-BOM.

Of course, you can format the code better.

CodePudding user response：

First, your path is wrong. type is not in the path down to test_number. The correct one would have been:

obj->RemovePair("Test.A.ins.id.values.test_number");

But as far as I know, that can't be parsed by RemovePair. You'll have to use FindValue:

// Cast helper:
TJSONObject* ToTJSONObject(TJSONValue* v) {
    if(!v) throw Exception("TJSONValue* == nullptr");
    return static_cast<TJSONObject*>(v);
}

auto obj = ToTJSONObject(TJSONObject::ParseJSONValue(...));
ToTJSONObject(obj->FindValue("Test.A.ins.id.values"))->RemovePair("test_number");