Visual FoxPro

Datev OAuth2 Access Token

See more Datev Examples

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

LOCAL lnSuccess
LOCAL loOauth2
LOCAL lcUrl
LOCAL lnNumMsWaited
LOCAL loSbJson

lnSuccess = 0

* To further clarify, see OAuth 2.0 Authorization Flow

loOauth2 = CreateObject('Chilkat.OAuth2')

* Your Datev app should use "http://localhost" (no trailing forward slash) for the redirect URL.
loOauth2.ListenPort = 3017

* 

loOauth2.AuthorizationEndpoint = "https://login.datev.de/openidsandbox/authorize"
loOauth2.TokenEndpoint = "https://sandbox-api.datev.de/token"

* Replace this with your actual client ID.
loOauth2.ClientId = "DATEV_CLIENT_ID"
loOauth2.ClientSecret = "DATEV_CLIENT_SECRET"

loOauth2.CodeChallenge = 1
loOauth2.CodeChallengeMethod = "S256"

loOauth2.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.
lcUrl = loOauth2.StartAuth()
IF (loOauth2.LastMethodSuccess <> 1) THEN
    ? loOauth2.LastErrorText
    RELEASE loOauth2
    CANCEL
ENDIF

* Launch the default browser on the system and navigate to the url.
* The LaunchBrowser method was added in Chilkat v10.1.2.
lnSuccess = loOauth2.LaunchBrowser(lcUrl)
IF (lnSuccess = 0) THEN
    ? loOauth2.LastErrorText
    RELEASE loOauth2
    CANCEL
ENDIF

* Wait for the interactive user to grant permission in the interactive browser session.
* We'll wait for a max of 90 seconds.
lnNumMsWaited = 0
DO WHILE (lnNumMsWaited < 90000) AND (loOauth2.AuthFlowState < 3)
    loOauth2.SleepMs(100)
    lnNumMsWaited = lnNumMsWaited + 100
ENDDO

* 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 (loOauth2.AuthFlowState < 3) THEN
    loOauth2.Cancel()
    ? "No response from the browser!"
    RELEASE loOauth2
    CANCEL
ENDIF

* 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 (loOauth2.AuthFlowState = 5) THEN
    ? "OAuth2 failed to complete."
    ? loOauth2.FailureInfo
    RELEASE loOauth2
    CANCEL
ENDIF

IF (loOauth2.AuthFlowState = 4) THEN
    ? "OAuth2 authorization was denied."
    ? loOauth2.AccessTokenResponse
    RELEASE loOauth2
    CANCEL
ENDIF

IF (loOauth2.AuthFlowState <> 3) THEN
    ? "Unexpected AuthFlowState:" + STR(loOauth2.AuthFlowState)
    RELEASE loOauth2
    CANCEL
ENDIF

* Save the full JSON access token response to a file.
loSbJson = CreateObject('Chilkat.StringBuilder')
loSbJson.Append(loOauth2.AccessTokenResponse)
loSbJson.WriteFile("qa_data/tokens/datev.json","utf-8",0)

* 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		
* }

? "OAuth2 authorization granted!"
? "Access Token = " + loOauth2.AccessToken

RELEASE loOauth2
RELEASE loSbJson