(MFC) Find a Label ID by Name

Lookup the ID of a GMail label by the label name.

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>

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");

    const char *userId = "me";
    http.SetUrlVar("userId",userId);

    const char *url = "https://www.googleapis.com/gmail/v1/users/{$userId}/labels";

    // Get the list of GMail labels as JSON.
    CkStringBuilder sb;
    success = http.QuickGetSb(url,sb);
    if (success != true) {
        strOut.append(http.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    CkJsonObject json;
    json.LoadSb(sb);
    json.put_EmitCompact(false);
    strOut.append(json.emit());
    strOut.append("\r\n");

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

    // The JSON returned looks like this:
    // {
    //   "labels": [
    //     {
    //       "id": "Label_5",
    //       "name": "QA",
    //       "messageListVisibility": "show",
    //       "labelListVisibility": "labelShow",
    //       "type": "user"
    //     },
    //     {
    //       "id": "Label_21",
    //       "name": "[Gmail]/testFolder",
    //       "type": "user"
    //     },
    //     {
    //       "id": "CATEGORY_PERSONAL",
    //       "name": "CATEGORY_PERSONAL",
    //       "type": "system"
    //     },
    // 	...

    // The name of the label is generally known because it's what we visually see.
    // The id is what we need to get.  Assuming the name is unique,
    // find the JSON record having name=<desired name>
    // For example...
    CkJsonObject *jRecord = json.FindRecord("labels","name","QA",false);
    if (json.get_LastMethodSuccess() == true) {
        strOut.append("The id of QA is: ");
        strOut.append(jRecord->stringOf("id"));
        strOut.append("\r\n");
        delete jRecord;
    }

    jRecord = json.FindRecord("labels","name","[Gmail]/testFolder",false);
    if (json.get_LastMethodSuccess() == true) {
        strOut.append("The id of [Gmail]/testFolder is: ");
        strOut.append(jRecord->stringOf("id"));
        strOut.append("\r\n");
        delete jRecord;
    }

    jRecord = json.FindRecord("labels","name","questions",false);
    if (json.get_LastMethodSuccess() == true) {
        strOut.append("The id of questions is: ");
        strOut.append(jRecord->stringOf("id"));
        strOut.append("\r\n");
        delete jRecord;
    }

    // Output:

    // The id of QA is: Label_5
    // The id of [Gmail]/testFolder is: Label_21
    // The id of questions is: Label_43


    SetDlgItemText(IDC_EDIT1,strOut.getUnicode());

    }