How to create JSON-file in Delphi using SuperObjec

Question

I'm using Delphi 2010 and superobject library.

I have understand how to parse json-file, but I have no ideas how to create json?

The algorithm is:

1. Parsing JSON and load in TStringGrid
2. Adding data
3. Save all TStringGrid data to json.

Need some example.

Thanks.

Answer 1

Code sample to feed following structure to JSON object, then save to file:

(*
{
  "name": "Henri Gourvest", /* this is a comment */
  "vip": true,
  "telephones": ["000000000", "111111111111"],
  "age": 33,
  "size": 1.83,
  "adresses": [
    {
      "adress": "blabla",
      "city": "Metz",
      "pc": 57000
    },
    {
      "adress": "blabla",
      "city": "Nantes",
      "pc": 44000
    }
  ]
}
*)

procedure SaveJson;
var
  json, json_sub: ISuperObject;
begin
  json := SO;

  json.S['name'] := 'Henri Gourvest';
  json.B['vip'] := TRUE;
  json.O['telephones'] := SA([]);
  json.A['telephones'].S[0] := '000000000';
  json.A['telephones'].S[1] := '111111111111';
  json.I['age'] := 33;
  json.D['size'] := 1.83;

  json.O['addresses'] := SA([]);

  json_sub := SO;
  json_sub.S['address'] := 'blabla';
  json_sub.S['city'] := 'Metz';
  json_sub.I['pc'] := 57000;
  json.A['addresses'].Add(json_sub);

  json_sub.S['address'] := 'blabla';
  json_sub.S['city'] := 'Nantes';
  json_sub.I['pc'] := 44000;
  json.A['addresses'].Add(json_sub);

  json.SaveTo('C:\json_out.txt');

  json := nil;
  json_sub := nil;
end;

Answer 2

Reading help file: https://github.com/hgourvest/superobject/blob/master/README.md

And then reading sources for TSuperArray ('Use the source, Luke')

Results in the following snippet:

var
  obj: ISuperObject;
  a:   TSuperArray; // shortcut
begin
  obj := TSuperObject.Create(stArray);
  // or obj := SA([]);

  a := obj.AsArray;

  a.s[0] := 'aaaa';
  a.s[1] := 'bbbb';
  a.s[3] := 'cccc';

  ...

  obj.SaveTo('File.txt');
  a := nil; obj := nil;

  ...
end;

---

There is also the quote from help file: obj['foo[]'] := value; // add an item array
This suggests another way to populate an array (if the root object itself is not an array). Quoting http://code.google.com/p/superobject/source/browse/tests/test_usage.dpr

my_array := TSuperObject.Create(stArray);
    my_array.I[''] := 1; // append
    my_array.I[''] := 2; // append
    my_array.I[''] := 3; // append
    my_array.I['4'] := 5;

And later this object-array is inserted as property into yet another object

    my_object := TSuperObject.Create(stObject);
    my_object.I['abc'] := 12;
   // my_object.S['path.to.foo[5]'] := 'bar';
    my_object.B['bool0'] := false;
    my_object.B['bool1'] := true;
    my_object.S['baz'] := 'bang';
    my_object.S['baz'] := 'fark';
    my_object.AsObject.Delete('baz');
    my_object['arr'] := my_array;

Answer 3

A very good library for that is the LkJson: http://sourceforge.net/projects/lkjson/

To parse:

var jsText : String; jsObj : TlkJSONobject; begin

jsObj:=TlkJSON.ParseText(jsText) as TlkJSONobject;

To convert it back into text:

jsText := TlkJSON.GenerateText(jsObj);