Unicode C

Get a Google People API OAuth2 Access Token

See more Google People Examples

Demonstrates how to get a Google People OAuth2 access token from a desktop application or script. Unicode C

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

void ChilkatSample(void)
    {
    BOOL success;
    HCkOAuth2W oauth2;
    const wchar_t *url;
    int numMsWaited;
    HCkStringBuilderW sbJson;

    success = FALSE;

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

    oauth2 = CkOAuth2W_Create();

    // For Google OAuth2, set the ListenPort equal to the port specified in the authorized callback URI for the ClientID.
    // See http://cknotes.com/setup-google-account-for-google-drive-api-walkthrough/
    CkOAuth2W_putListenPort(oauth2,3017);

    CkOAuth2W_putAuthorizationEndpoint(oauth2,L"https://accounts.google.com/o/oauth2/v2/auth");
    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");

    CkOAuth2W_putCodeChallenge(oauth2,TRUE);
    CkOAuth2W_putCodeChallengeMethod(oauth2,L"S256");

    // See Google People API Scopes for more scopes.
    CkOAuth2W_putScope(oauth2,L"profile https://www.googleapis.com/auth/contacts https://www.googleapis.com/auth/contacts.other.readonly https://www.googleapis.com/auth/directory.readonly");

    // Begin the OAuth2 three-legged flow.  This returns a URL that should be loaded in a browser.
    url = CkOAuth2W_startAuth(oauth2);
    if (CkOAuth2W_getLastMethodSuccess(oauth2) == FALSE) {
        wprintf(L"%s\n",CkOAuth2W_lastErrorText(oauth2));
        CkOAuth2W_Dispose(oauth2);
        return;
    }

    // Launch the system's default browser navigated to the URL.
    success = CkOAuth2W_LaunchBrowser(oauth2,url);
    if (success == FALSE) {
        wprintf(L"%s\n",CkOAuth2W_lastErrorText(oauth2));
        CkOAuth2W_Dispose(oauth2);
        return;
    }

    // Now wait for the authorization.
    // We'll wait for a max of 30 seconds.
    numMsWaited = 0;
    while ((numMsWaited < 30000) && (CkOAuth2W_getAuthFlowState(oauth2) < 3)) {
        CkOAuth2W_SleepMs(oauth2,100);
        numMsWaited = numMsWaited + 100;
    }

    // If there was no response from the browser within 30 seconds, then 
    // the AuthFlowState will be equal to 1 or 2.
    // 1: Waiting for Redirect. The OAuth2 background thread is waiting to receive the redirect HTTP request from the browser.
    // 2: Waiting for Final Response. The OAuth2 background thread is waiting for the final access token response.
    // In that case, cancel the background task started in the call to StartAuth.
    if (CkOAuth2W_getAuthFlowState(oauth2) < 3) {
        CkOAuth2W_Cancel(oauth2);
        wprintf(L"No response from the browser!\n");
        CkOAuth2W_Dispose(oauth2);
        return;
    }

    // Check the AuthFlowState to see if authorization was granted, denied, or if some error occurred
    // The possible AuthFlowState values are:
    // 3: Completed with Success. The OAuth2 flow has completed, the background thread exited, and the successful JSON response is available in AccessTokenResponse property.
    // 4: Completed with Access Denied. The OAuth2 flow has completed, the background thread exited, and the error JSON is available in AccessTokenResponse property.
    // 5: Failed Prior to Completion. The OAuth2 flow failed to complete, the background thread exited, and the error information is available in the FailureInfo property.
    if (CkOAuth2W_getAuthFlowState(oauth2) == 5) {
        wprintf(L"OAuth2 failed to complete.\n");
        wprintf(L"%s\n",CkOAuth2W_failureInfo(oauth2));
        CkOAuth2W_Dispose(oauth2);
        return;
    }

    if (CkOAuth2W_getAuthFlowState(oauth2) == 4) {
        wprintf(L"OAuth2 authorization was denied.\n");
        wprintf(L"%s\n",CkOAuth2W_accessTokenResponse(oauth2));
        CkOAuth2W_Dispose(oauth2);
        return;
    }

    if (CkOAuth2W_getAuthFlowState(oauth2) != 3) {
        wprintf(L"Unexpected AuthFlowState:%d\n",CkOAuth2W_getAuthFlowState(oauth2));
        CkOAuth2W_Dispose(oauth2);
        return;
    }

    // Save the full JSON access token response to a file.
    sbJson = CkStringBuilderW_Create();
    CkStringBuilderW_Append(sbJson,CkOAuth2W_accessTokenResponse(oauth2));
    CkStringBuilderW_WriteFile(sbJson,L"qa_data/tokens/googlePeople.json",L"utf-8",FALSE);

    // The saved JSON response 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"
    // }

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


    CkOAuth2W_Dispose(oauth2);
    CkStringBuilderW_Dispose(sbJson);

    }