B4X Requires Chilkat v10.1.2+

GeoOp OAuth2 Authorisation Code Grant (Public App)

See more OAuth2 Examples

Demonstrates how to get an access token for a GeoOp Third-Party Public Application using the Authorisation Code Grant flow. B4X

Dim success As Boolean = False

'  It requires the Chilkat API to have been previously unlocked.
'  See Global Unlock Sample for sample code.

Dim oauth2 As ChilkatOAuth2
oauth2.Initialize("oauth2")

'  This should match the Site URL configured for your GeoOp (non-Server) Application, such as "http://localhost:3017/"
oauth2.ListenPort = 3017

oauth2.AuthorizationEndpoint = "https://login.geoop.com/oauth2/code"
oauth2.TokenEndpoint = "https://login.geoop.com/oauth2/token"

'  Replace the client ID with an actual value.
oauth2.ClientId = "GEOOP-APPLICATION-ID"
'  The ClientSecret should remain empty for a GeoOp public application
oauth2.ClientSecret = ""

'  We need a few special settings for GeoOp
oauth2.Scope = "default"
oauth2.CodeChallenge = False
'  Setting LocalHost equal to "none" prevents the "redirect_uri" query param from being sent in the initial HTTP request.
'  Note: The GeoOp Application should still have a redirect URL specified as "http://localhost:3017/", where the port
'  number matches the ListenPort above.
oauth2.LocalHost = "none"

'  Begin the OAuth2 Authorization code flow.  This returns a URL that should be loaded in a browser.
Dim url As String = oauth2.StartAuth
If oauth2.LastMethodSuccess <> True Then
    Log(oauth2.LastErrorText)
    Return
End If


'  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 Then
    Log(oauth2.LastErrorText)
    Return
End If


'  Wait for the user to approve or deny authorization in the browser.
Dim numMsWaited As Int = 0
Do While (numMsWaited < 90000) And (oauth2.AuthFlowState < 3)
    oauth2.SleepMs(100)
    numMsWaited = numMsWaited + 100
Loop

'  If the browser does not respond within the specified time, AuthFlowState will be:
'  
'  1: Waiting for Redirect – The OAuth2 background thread is waiting for the browser's redirect request.
'  2: Waiting for Final Response – The thread is awaiting the final access token response.
'  In either case, cancel the background task initiated by StartAuth.

If oauth2.AuthFlowState < 3 Then
    oauth2.Cancel
    Log("No response from the browser!")
    Return
End If


'  Check AuthFlowState to determine if authorization was granted, denied, or failed:
'  
'  3: Success – OAuth2 flow completed, the background thread exited, and the successful response is in AccessTokenResponse.
'  4: Access Denied – OAuth2 flow completed, the background thread exited, and the error response is in AccessTokenResponse.
'  5: Failure – OAuth2 flow failed before completion, the background thread exited, and error details are in FailureInfo.

If oauth2.AuthFlowState = 5 Then
    Log("OAuth2 failed to complete.")
    Log(oauth2.FailureInfo)
    Return
End If


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


If oauth2.AuthFlowState <> 3 Then
    Log("Unexpected AuthFlowState:" & oauth2.AuthFlowState)
    Return
End If

Log("OAuth2 authorization granted!")
Log("Access Token = " & oauth2.AccessToken)

'  Save the entire JSON response, which includes the access token, for future calls.
'  The JSON AccessTokenResponse looks like this:
'  {"access_token":"e6dqdG....mzjpT04w==","token_type":"Bearer","expires_in":2592000,"owner_id":984236}

Dim fac As ChilkatFileAccess
fac.Initialize
fac.WriteEntireTextFile("qa_data/tokens/geoop.json", oauth2.AccessTokenResponse, "utf-8", False)

Log("Success.")