(Unicode C) Automatically Refresh Token for 401 Unauthorized

Demonstrates how to automatically refresh an access token (without user interaction) when the token expires and a 401 Unauthorized response is received.

Chilkat C/C++ Library Downloads
MS Visual C/C++ Linux/CentOS C/C++ Alpine Linux C/C++ MAC OS X C/C++	armhf/aarch64 C/C++ C++ Builder iOS C/C++ Android C/C++	Solaris C/C++ MinGW C/C++

#include <C_CkJsonObjectW.h>
#include <C_CkHttpW.h>
#include <C_CkOAuth2W.h>
#include <C_CkStringBuilderW.h>

void ChilkatSample(void)
    {
    const wchar_t *tokenFilePath;
    HCkJsonObjectW jsonToken;
    BOOL success;
    HCkHttpW http;
    const wchar_t *jsonResponse;
    HCkOAuth2W oauth2;
    HCkStringBuilderW sbJson;

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

    tokenFilePath = L"qa_data/tokens/googleCalendar.json";

    // Get our current access token.
    jsonToken = CkJsonObjectW_Create();
    success = CkJsonObjectW_LoadFile(jsonToken,tokenFilePath);
    if (CkJsonObjectW_HasMember(jsonToken,L"access_token") == FALSE) {
        wprintf(L"No access token found.\n");
        CkJsonObjectW_Dispose(jsonToken);
        return;
    }

    http = CkHttpW_Create();
    CkHttpW_putAuthToken(http,CkJsonObjectW_stringOf(jsonToken,L"access_token"));

    jsonResponse = CkHttpW_quickGetStr(http,L"https://www.googleapis.com/calendar/v3/users/me/calendarList");
    if (CkHttpW_getLastMethodSuccess(http) != TRUE) {

        if (CkHttpW_getLastStatus(http) != 401) {
            wprintf(L"%s\n",CkHttpW_lastErrorText(http));
            wprintf(L"----\n");
            wprintf(L"%s\n",CkHttpW_lastResponseBody(http));
            CkJsonObjectW_Dispose(jsonToken);
            CkHttpW_Dispose(http);
            return;
        }

        // The access token must've expired. 
        // Refresh the access token and then retry the request.
        oauth2 = CkOAuth2W_Create();

        CkOAuth2W_putTokenEndpoint(oauth2,L"https://www.googleapis.com/oauth2/v4/token");

        // Replace these with actual values.
        CkOAuth2W_putClientId(oauth2,L"GOOGLE-CLIENT-ID");
        CkOAuth2W_putClientSecret(oauth2,L"GOOGLE-CLIENT-SECRET");

        // Get the "refresh_token"
        CkOAuth2W_putRefreshToken(oauth2,CkJsonObjectW_stringOf(jsonToken,L"refresh_token"));

        // Send the HTTP POST to refresh the access token..
        success = CkOAuth2W_RefreshAccessToken(oauth2);
        if (success != TRUE) {
            wprintf(L"%s\n",CkOAuth2W_lastErrorText(oauth2));
            CkJsonObjectW_Dispose(jsonToken);
            CkHttpW_Dispose(http);
            CkOAuth2W_Dispose(oauth2);
            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.
        CkJsonObjectW_UpdateString(jsonToken,L"access_token",CkOAuth2W_accessToken(oauth2));

        // Save the new JSON access token response to a file.
        sbJson = CkStringBuilderW_Create();
        CkJsonObjectW_putEmitCompact(jsonToken,FALSE);
        CkJsonObjectW_EmitSb(jsonToken,sbJson);
        CkStringBuilderW_WriteFile(sbJson,tokenFilePath,L"utf-8",FALSE);

        wprintf(L"OAuth2 authorization granted!\n");
        wprintf(L"New Access Token = %s\n",CkOAuth2W_accessToken(oauth2));

        // re-try the original request.
        CkHttpW_putAuthToken(http,CkOAuth2W_accessToken(oauth2));
        jsonResponse = CkHttpW_quickGetStr(http,L"https://www.googleapis.com/calendar/v3/users/me/calendarList");
        if (CkHttpW_getLastMethodSuccess(http) != TRUE) {
            wprintf(L"%s\n",CkHttpW_lastErrorText(http));
            CkJsonObjectW_Dispose(jsonToken);
            CkHttpW_Dispose(http);
            CkOAuth2W_Dispose(oauth2);
            CkStringBuilderW_Dispose(sbJson);
            return;
        }

    }

    wprintf(L"%s\n",jsonResponse);
    wprintf(L"-----------------------------\n");


    CkJsonObjectW_Dispose(jsonToken);
    CkHttpW_Dispose(http);
    CkOAuth2W_Dispose(oauth2);
    CkStringBuilderW_Dispose(sbJson);

    }