Visual FoxPro Requires Chilkat v10.1.2+

Google OAuth2 Access Token

See more OAuth2 Examples

Demonstrates how to get a Google OAuth2 access token from a desktop application or script. Visual FoxPro

LOCAL lnSuccess
LOCAL loOauth2
LOCAL lcUrl
LOCAL lnNumMsWaited
LOCAL loSbJson

lnSuccess = 0

*  To further clarify, see OAuth 2.0 Authorization Flow

loOauth2 = CreateObject('Chilkat.OAuth2')

*  For Google OAuth2, set the listen port equal to the port used
*  in the Authorized Redirect URL for the Client ID.
*  For example, in this case the Authorized Redirect URL would be http://localhost:55568/
*  Your app should choose a port not likely not used by another application.
loOauth2.ListenPort = 55568

loOauth2.AuthorizationEndpoint = "https://accounts.google.com/o/oauth2/v2/auth"
loOauth2.TokenEndpoint = "https://www.googleapis.com/oauth2/v4/token"

*  Replace this with your actual client ID.
loOauth2.ClientId = "GOOGLE-CLIENT-ID"

*  This is the scope for Google Drive.
*  See https://developers.google.com/identity/protocols/googlescopes
*  Add the scopes that you need.
loOauth2.Scope = "https://www.googleapis.com/auth/drive"

*  Begin the OAuth2 authorization code flow.  This returns a URL that should be loaded in a browser.
lcUrl = loOauth2.StartAuth()
IF (loOauth2.LastMethodSuccess <> 1) THEN
    ? loOauth2.LastErrorText
    RELEASE loOauth2
    CANCEL
ENDIF

*  Launch the default browser on the system and navigate to the url.
*  The LaunchBrowser method was added in Chilkat v10.1.2.
lnSuccess = loOauth2.LaunchBrowser(lcUrl)
IF (lnSuccess = 0) THEN
    ? loOauth2.LastErrorText
    RELEASE loOauth2
    CANCEL
ENDIF

*  Wait for the interactive user to grant permission in the interactive browser session.
*  We'll wait for a max of 90 seconds.
lnNumMsWaited = 0
DO WHILE (lnNumMsWaited < 90000) AND (loOauth2.AuthFlowState < 3)
    loOauth2.SleepMs(100)
    lnNumMsWaited = lnNumMsWaited + 100
ENDDO

*  If there was no response from the browser within 90 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 (loOauth2.AuthFlowState < 3) THEN
    loOauth2.Cancel()
    ? "No response from the browser!"
    RELEASE loOauth2
    CANCEL
ENDIF

*  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 (loOauth2.AuthFlowState = 5) THEN
    ? "OAuth2 failed to complete."
    ? loOauth2.FailureInfo
    RELEASE loOauth2
    CANCEL
ENDIF

IF (loOauth2.AuthFlowState = 4) THEN
    ? "OAuth2 authorization was denied."
    ? loOauth2.AccessTokenResponse
    RELEASE loOauth2
    CANCEL
ENDIF

IF (loOauth2.AuthFlowState <> 3) THEN
    ? "Unexpected AuthFlowState:" + STR(loOauth2.AuthFlowState)
    RELEASE loOauth2
    CANCEL
ENDIF

*  Save the full JSON access token response to a file.
loSbJson = CreateObject('Chilkat.StringBuilder')
loSbJson.Append(loOauth2.AccessTokenResponse)
loSbJson.WriteFile("qa_data/tokens/_googleDrive.json","utf-8",0)

*  The saved JSON response looks like this:

*  	{
*  	 "access_token": "ya39.Ci-XA_C5bGgRDC3UaD-h0_NeL-DVIQnI2gHtBBBHkZzrwlARkwX6R3O0PCDEzRlfaQ",
*  	 "token_type": "Bearer",
*  	 "expires_in": 3600,
*  	 "refresh_token": "1/r_2c_7jddspcdfesrrfKqfXtqo08D6Q-gUU0DsdfVMsx0c"
*  	}
*  
? "OAuth2 authorization granted!"
? "Access Token = " + loOauth2.AccessToken

*  Here is an example showing how to define your OAuth 2.0 Credential in the Google Cloud Console
*  Note: Even though your application is technically not a web app, you should still select "Web Application"
*  because the Redirect URI is going to http://localhost:55568/ where Chilkat will receive it in a background thread.

*  

RELEASE loOauth2
RELEASE loSbJson