Go 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. Go

    success := false

    //  To further clarify, see OAuth 2.0 Authorization Flow

    oauth2 := chilkat.NewOAuth2()

    //  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.
    oauth2.SetListenPort(55568)

    oauth2.SetAuthorizationEndpoint("https://accounts.google.com/o/oauth2/v2/auth")
    oauth2.SetTokenEndpoint("https://www.googleapis.com/oauth2/v4/token")

    //  Replace this with your actual client ID.
    oauth2.SetClientId("GOOGLE-CLIENT-ID")

    //  This is the scope for Google Drive.
    //  See https://developers.google.com/identity/protocols/googlescopes
    //  Add the scopes that you need.
    oauth2.SetScope("https://www.googleapis.com/auth/drive")

    //  Begin the OAuth2 authorization code flow.  This returns a URL that should be loaded in a browser.
    url := oauth2.StartAuth()
    if oauth2.LastMethodSuccess() != true {
        fmt.Println(oauth2.LastErrorText())
        oauth2.DisposeOAuth2()
        return
    }

    //  Launch the default browser on the system and navigate to the url.
    //  The LaunchBrowser method was added in Chilkat v10.1.2.
    success = oauth2.LaunchBrowser(*url)
    if success == false {
        fmt.Println(oauth2.LastErrorText())
        oauth2.DisposeOAuth2()
        return
    }

    //  Wait for the interactive user to grant permission in the interactive browser session.
    //  We'll wait for a max of 90 seconds.
    numMsWaited := 0
    for (numMsWaited < 90000) && (oauth2.AuthFlowState() < 3) {
        oauth2.SleepMs(100)
        numMsWaited = numMsWaited + 100
    }

    //  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 oauth2.AuthFlowState() < 3 {
        oauth2.Cancel()
        fmt.Println("No response from the browser!")
        oauth2.DisposeOAuth2()
        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 oauth2.AuthFlowState() == 5 {
        fmt.Println("OAuth2 failed to complete.")
        fmt.Println(oauth2.FailureInfo())
        oauth2.DisposeOAuth2()
        return
    }

    if oauth2.AuthFlowState() == 4 {
        fmt.Println("OAuth2 authorization was denied.")
        fmt.Println(oauth2.AccessTokenResponse())
        oauth2.DisposeOAuth2()
        return
    }

    if oauth2.AuthFlowState() != 3 {
        fmt.Println("Unexpected AuthFlowState:", oauth2.AuthFlowState())
        oauth2.DisposeOAuth2()
        return
    }

    //  Save the full JSON access token response to a file.
    sbJson := chilkat.NewStringBuilder()
    sbJson.Append(oauth2.AccessTokenResponse())
    sbJson.WriteFile("qa_data/tokens/_googleDrive.json","utf-8",false)

    //  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"
    //  	}
    //  
    fmt.Println("OAuth2 authorization granted!")
    fmt.Println("Access Token = ", oauth2.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.

    //  

    oauth2.DisposeOAuth2()
    sbJson.DisposeStringBuilder()