(Visual Basic 6.0) GeoOp OAuth2 Authorisation Code Grant (Public App)

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

Note: This example requires Chilkat v9.5.0.63 or greater.

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

' Note: This example requires Chilkat v9.5.0.63 or greater.

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

Dim oauth2 As New ChilkatOAuth2
Dim success As Long

' This should match the Site URL configured for your GeoOp 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-CLIENT-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 = 0
' 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 three-legged flow.  This returns a URL that should be loaded in a browser.
Dim url As String
url = oauth2.StartAuth()
If (oauth2.LastMethodSuccess <> 1) Then
    Debug.Print oauth2.LastErrorText
    Exit Sub
End If

' At this point, your application should load the URL in a browser.
' For example, 
' in C#:  System.Diagnostics.Process.Start(url);
' in Java: Desktop.getDesktop().browse(new URI(url));
' in VBScript: Set wsh=WScript.CreateObject("WScript.Shell")
'              wsh.Run url
' in Xojo: ShowURL(url)  (see http://docs.xojo.com/index.php/ShowURL)
' in Dataflex: Runprogram Background "c:\Program Files\Internet Explorer\iexplore.exe" sUrl        
' The GeoOp account owner would interactively accept or deny the authorization request.
' System.Diagnostics.Process.Start(url);

' Add the code to load the url in a web browser here...
' Add the code to load the url in a web browser here...
' Add the code to load the url in a web browser here...

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

' 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()
    Debug.Print "No response from the browser!"
    Exit Sub
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
    Debug.Print "OAuth2 failed to complete."
    Debug.Print oauth2.FailureInfo
    Exit Sub
End If

If (oauth2.AuthFlowState = 4) Then
    Debug.Print "OAuth2 authorization was denied."
    Debug.Print oauth2.AccessTokenResponse
    Exit Sub
End If

If (oauth2.AuthFlowState <> 3) Then
    Debug.Print "Unexpected AuthFlowState:" & oauth2.AuthFlowState
    Exit Sub
End If

Debug.Print "OAuth2 authorization granted!"
Debug.Print "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 New CkFileAccess
success = fac.WriteEntireTextFile("qa_data/tokens/geoop.json",oauth2.AccessTokenResponse,"utf-8",0)

Debug.Print "Success."