(Swift) Google OAuth2 Access Token

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

Note: This example requires Chilkat v10.1.2 or later.

Chilkat Downloads for the Swift Programming Language MAC OS X (Cocoa) Objective-C/Swift Libs iOS Objective-C/Swift Libs

func chilkatTest() {
    // To further clarify, see OAuth 2.0 Authorization Flow

    let oauth2 = CkoOAuth2()!

    // 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.listenPort = 55568

    oauth2.authorizationEndpoint = "https://accounts.google.com/o/oauth2/v2/auth"
    oauth2.tokenEndpoint = "https://www.googleapis.com/oauth2/v4/token"

    // Replace this with your actual client ID.
    oauth2.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.
    oauth2.scope = "https://www.googleapis.com/auth/drive"

    // Begin the OAuth2 authorization code flow.  This returns a URL that should be loaded in a browser.
    var url: String? = oauth2.start()
    if oauth2.lastMethodSuccess != true {
        print("\(oauth2.lastErrorText!)")
        return
    }

    // Launch the default browser on the system and navigate to the url.
    // The LaunchBrowser method was added in Chilkat v10.1.2.
    var success: Bool = oauth2.launchBrowser(url)
    if success == false {
        print("\(oauth2.lastErrorText!)")
        return
    }

    // Wait for the interactive user to grant permission in the interactive browser session.
    // We'll wait for a max of 90 seconds.
    var numMsWaited: Int = 0
    while (numMsWaited < 90000) && (oauth2.authFlowState.intValue < 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.intValue < 3 {
        oauth2.cancel()
        print("No response from the browser!")
        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.intValue == 5 {
        print("OAuth2 failed to complete.")
        print("\(oauth2.failureInfo!)")
        return
    }

    if oauth2.authFlowState.intValue == 4 {
        print("OAuth2 authorization was denied.")
        print("\(oauth2.accessTokenResponse!)")
        return
    }

    if oauth2.authFlowState.intValue != 3 {
        print("Unexpected AuthFlowState:\(oauth2.authFlowState.intValue)")
        return
    }

    // Save the full JSON access token response to a file.
    let sbJson = CkoStringBuilder()!
    sbJson.append(oauth2.accessTokenResponse)
    sbJson.writeFile("qa_data/tokens/_googleDrive.json", charset: "utf-8", emitBom: 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"
    // 	}
    // 
    print("OAuth2 authorization granted!")
    print("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.

    // 

}