(MFC) 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 C/C++ Library Downloads MS Visual C/C++ Libs

See Also: Using MFC CString in Chilkat

#include <CkJsonObject.h>

void ChilkatSample(void)
    {
    CkString strOut;

    CkJsonObject json;

    // 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. 
    const char *jsonStr = "{\"name\": \"donut\",\"image\":{\"fname\": \"donut.jpg\",\"w\": 200,\"h\": 200},\"thumbnail\":{\"fname\": \"donutThumb.jpg\",\"w\": 32,\"h\": 32}}";

    bool success = json.Load(jsonStr);
    if (success != true) {
        strOut.append(json.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    // Get the "image" object.
    CkJsonObject *imageObj = json.ObjectOf("image");
    if (json.get_LastMethodSuccess() == false) {
        strOut.append("image object not found.");
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    strOut.append("image: fname=");
    strOut.append(imageObj->stringOf("fname"));
    strOut.append(", width=");
    strOut.appendInt(imageObj->IntOf("w"));
    strOut.append(", height=");
    strOut.appendInt(imageObj->IntOf("h"));
    strOut.append("\r\n");

    delete imageObj;

    // Get the "thumbnail" object.
    CkJsonObject *thumbObj = json.ObjectOf("thumbnail");
    if (json.get_LastMethodSuccess() == false) {
        strOut.append("thumbnail object not found.");
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    strOut.append("thumbnail: fname=");
    strOut.append(thumbObj->stringOf("fname"));
    strOut.append(", width=");
    strOut.appendInt(thumbObj->IntOf("w"));
    strOut.append(", height=");
    strOut.appendInt(thumbObj->IntOf("h"));
    strOut.append("\r\n");

    delete thumbObj;


    SetDlgItemText(IDC_EDIT1,strOut.getUnicode());

    }