B4X Requires Chilkat v10.1.3+

Datev OAuth2 Access Token

See more Datev Examples

Demonstrates how to get a Datev OAuth2 access token from a desktop application or script. B4X

Dim success As Boolean = False

'  To further clarify, see OAuth 2.0 Authorization Flow

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

'  Your Datev app should use "http://localhost" (no trailing forward slash) for the redirect URL.
oauth2.ListenPort = 3017

'  

oauth2.AuthorizationEndpoint = "https://login.datev.de/openidsandbox/authorize"
oauth2.TokenEndpoint = "https://sandbox-api.datev.de/token"

'  Replace this with your actual client ID.
oauth2.ClientId = "DATEV_CLIENT_ID"
oauth2.ClientSecret = "DATEV_CLIENT_SECRET"

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

oauth2.Scope = "openid profile email datev:accounting:clients accounting:documents datev:accounting:extf-files-import"

'  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 interactive user to grant permission in the interactive browser session.
'  We'll wait for a max of 90 seconds.
Dim numMsWaited As Int = 0
Do While (numMsWaited < 90000) And (oauth2.AuthFlowState < 3)
    oauth2.SleepMs(100)
    numMsWaited = numMsWaited + 100
Loop

'  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 Then
    oauth2.Cancel
    Log("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
    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


'  Save the full JSON access token response to a file.
Dim sbJson As ChilkatStringBuilder
sbJson.Initialize
sbJson.Append(oauth2.AccessTokenResponse)
sbJson.WriteFile("qa_data/tokens/datev.json", "utf-8", False)

'  The saved JSON response looks like this:

'  {
'  	"refresh_token": "ZDA5Y .... FFhTXc9",
'  	"refresh_token_expires_in": 39600,
'  	"id_token": "eyJ .... Q9w",
'  	"access_token": "MTM .... 1UDA9",
'  	"token_type": "bearer",
'  	"expires_in": 900		
'  }

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