(MFC) Download a Specific GMail Message into a Chilkat Email Object

Demonstrates how to download a GMail message into a Chilkat Email object.

Chilkat C/C++ Library Downloads MS Visual C/C++ Libs

See Also: Using MFC CString in Chilkat

#include <CkHttp.h>
#include <CkStringBuilder.h>
#include <CkJsonObject.h>
#include <CkEmail.h>

void ChilkatSample(void)
    {
    CkString strOut;

    // This example requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    bool success;

    CkHttp http;
    http.put_AuthToken("GMAIL-ACCESS-TOKEN");

    // The id of the GMail message to download.
    const char *id = "166e50fed0b9b0cb";
    const char *userId = "me";

    http.SetUrlVar("userId","me");
    http.SetUrlVar("id",id);

    // Fetch the email.
    const char *url = "https://www.googleapis.com/gmail/v1/users/{$userId}/messages/{$id}?format=raw";
    CkStringBuilder sbJson;
    success = http.DownloadSb(url,"utf-8",sbJson);
    if (success != true) {
        strOut.append(http.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    CkJsonObject json;
    json.LoadSb(sbJson);
    json.put_EmitCompact(false);

    if (http.get_LastStatus() != 200) {
        strOut.append(json.emit());
        strOut.append("\r\n");
        strOut.append("Failed.");
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    // The returned JSON contains something like this:

    // {
    //   "id": "166e50fed0b9b0cb",
    //   "threadId": "166e50fed0b9b0cb",
    //   "labelIds": [
    //     "CATEGORY_SOCIAL",
    //     "INBOX"
    //   ],
    //   "snippet": "...",
    //   "historyId": "582477",
    //   "internalDate": "1541441317000",
    //   "sizeEstimate": 28603,
    //   "raw": "BASE64URL_CONTENT"
    // }

    // The RFC822 MIME of the email is contained in the "raw" as a base64URL encoded string.
    // Let's decode and load into a Chilkat email object..
    CkStringBuilder sbRaw;
    json.StringOfSb("raw",sbRaw);
    sbRaw.Decode("base64url","utf-8");

    CkEmail email;
    email.SetFromMimeSb(sbRaw);

    // Now we can use the email API to do whatever we desire..
    strOut.append("From: ");
    strOut.append(email.fromAddress());
    strOut.append("\r\n");
    strOut.append("Subject: ");
    strOut.append(email.subject());
    strOut.append("\r\n");
    // ...


    SetDlgItemText(IDC_EDIT1,strOut.getUnicode());

    }