(Delphi DLL) JSON: Nested Objects

Here we have a JSON object that contains nested JSON objects. This example demonstrates how to access the contents of the nested objects.

{
  "name": "donut",
  "image":
    {
    "fname": "donut.jpg",
    "w": 200,
    "h": 200
    },
  "thumbnail":
    {
    "fname": "donutThumb.jpg",
    "w": 32,
    "h": 32
    }
}

Chilkat for Delphi Downloads Chilkat non-ActiveX DLL for Delphi Chilkat ActiveX DLL for Delphi * The examples here use the non-ActiveX DLL.

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, JsonObject;

...

procedure TForm1.Button1Click(Sender: TObject);
var
json: HCkJsonObject;
jsonStr: PWideChar;
success: Boolean;
imageObj: HCkJsonObject;
thumbObj: HCkJsonObject;

begin
json := CkJsonObject_Create();

// This is the above JSON with whitespace chars removed (SPACE, TAB, CR, and LF chars).
// The presence of whitespace chars for pretty-printing makes no difference to the Load
// method. 
jsonStr := '{"name": "donut","image":{"fname": "donut.jpg","w": 200,"h": 200},"thumbnail":{"fname": "donutThumb.jpg","w": 32,"h": 32}}';

success := CkJsonObject_Load(json,jsonStr);
if (success <> True) then
  begin
    Memo1.Lines.Add(CkJsonObject__lastErrorText(json));
    Exit;
  end;

// Get the "image" object.
imageObj := CkJsonObject_ObjectOf(json,'image');
if (CkJsonObject_getLastMethodSuccess(json) = False) then
  begin
    Memo1.Lines.Add('image object not found.');
    Exit;
  end;

Memo1.Lines.Add('image: fname=' + CkJsonObject__stringOf(imageObj,'fname') + ', width=' + IntToStr(CkJsonObject_IntOf(imageObj,'w'))
     + ', height=' + IntToStr(CkJsonObject_IntOf(imageObj,'h')));

CkJsonObject_Dispose(imageObj);

// Get the "thumbnail" object.
thumbObj := CkJsonObject_ObjectOf(json,'thumbnail');
if (CkJsonObject_getLastMethodSuccess(json) = False) then
  begin
    Memo1.Lines.Add('thumbnail object not found.');
    Exit;
  end;

Memo1.Lines.Add('thumbnail: fname=' + CkJsonObject__stringOf(thumbObj,'fname') + ', width=' + IntToStr(CkJsonObject_IntOf(thumbObj,'w'))
     + ', height=' + IntToStr(CkJsonObject_IntOf(thumbObj,'h')));

CkJsonObject_Dispose(thumbObj);

CkJsonObject_Dispose(json);

end;