(MFC) Google People API Refresh Access Token

Demonstrates how to refresh a Google Access Token for the Google People API.

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

See Also: Using MFC CString in Chilkat

#include <CkJsonObject.h>
#include <CkOAuth2.h>
#include <CkStringBuilder.h>

void ChilkatSample(void)
    {
    CkString strOut;

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

    // It is assumed we previously obtained an OAuth2 access token.
    // This example loads the JSON access token file 
    // saved by this example: Get Google People API OAuth2 Access Token

    CkJsonObject jsonToken;
    bool success = jsonToken.LoadFile("qa_data/tokens/googlePeople.json");
    if (success != true) {
        strOut.append("Failed to load googlePeople.json");
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    // The access token JSON looks like this:

    // {
    //   "access_token": "ya29.a0AfH6S ... LAZYFUkf0",
    //   "expires_in": 3599,
    //   "refresh_token": "1//0fL_Ov ... ee0",
    //   "scope": "https://www.googleapis.com/auth/contacts",
    //   "token_type": "Bearer"
    // }

    CkOAuth2 oauth2;

    oauth2.put_TokenEndpoint("https://www.googleapis.com/oauth2/v4/token");

    // Replace these with actual values.
    oauth2.put_ClientId("GOOGLE-CLIENT-ID");
    oauth2.put_ClientSecret("GOOGLE-CLIENT-SECRET");

    // Get the "refresh_token"
    oauth2.put_RefreshToken(jsonToken.stringOf("refresh_token"));

    // Send the HTTP POST to refresh the access token..
    success = oauth2.RefreshAccessToken();
    if (success != true) {
        strOut.append(oauth2.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    // The response contains a new access token, but we must keep
    // our existing refresh token for when we need to refresh again in the future.
    jsonToken.UpdateString("access_token",oauth2.accessToken());

    // Save the new JSON access token response to a file.
    CkStringBuilder sbJson;
    jsonToken.put_EmitCompact(false);
    jsonToken.EmitSb(sbJson);
    sbJson.WriteFile("qa_data/tokens/googlePeople.json","utf-8",false);

    strOut.append("OAuth2 authorization granted!");
    strOut.append("\r\n");
    strOut.append("New Access Token = ");
    strOut.append(oauth2.accessToken());
    strOut.append("\r\n");


    SetDlgItemText(IDC_EDIT1,strOut.getUnicode());

    }