Xojo Plugin

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. Xojo Plugin

Dim success As Boolean
success = False

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

Dim oauth2 As New Chilkat.OAuth2

// 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/
oauth2.ListenPort = 3017

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

// Replace these with actual values.
oauth2.ClientId = "GOOGLE-CLIENT-ID"
oauth2.ClientSecret = "GOOGLE-CLIENT-SECRET"

oauth2.CodeChallenge = True
oauth2.CodeChallengeMethod = "S256"

// See Google People API Scopes for more scopes.
oauth2.Scope = "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.
Dim url As String
url = oauth2.StartAuth()
If (oauth2.LastMethodSuccess = False) Then
    System.DebugLog(oauth2.LastErrorText)
    Return
End If

// Launch the system's default browser navigated to the URL.
success = oauth2.LaunchBrowser(url)
If (success = False) Then
    System.DebugLog(oauth2.LastErrorText)
    Return
End If

// Now wait for the authorization.
// We'll wait for a max of 30 seconds.
Dim numMsWaited As Int32
numMsWaited = 0
While (numMsWaited < 30000) And (oauth2.AuthFlowState < 3)
    oauth2.SleepMs 100
    numMsWaited = numMsWaited + 100
Wend

// 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 (oauth2.AuthFlowState < 3) Then
    success = oauth2.Cancel()
    System.DebugLog("No response from the browser!")
    Return
End If

// 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) Then
    System.DebugLog("OAuth2 failed to complete.")
    System.DebugLog(oauth2.FailureInfo)
    Return
End If

If (oauth2.AuthFlowState = 4) Then
    System.DebugLog("OAuth2 authorization was denied.")
    System.DebugLog(oauth2.AccessTokenResponse)
    Return
End If

If (oauth2.AuthFlowState <> 3) Then
    System.DebugLog("Unexpected AuthFlowState:" + Str(oauth2.AuthFlowState))
    Return
End If

// Save the full JSON access token response to a file.
Dim sbJson As New Chilkat.StringBuilder
success = sbJson.Append(oauth2.AccessTokenResponse)
success = sbJson.WriteFile("qa_data/tokens/googlePeople.json","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"
// }

System.DebugLog("OAuth2 authorization granted!")
System.DebugLog("Access Token = " + oauth2.AccessToken)