PureBasic

Datev OAuth2 Access Token

See more Datev Examples

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

IncludeFile "CkOAuth2.pb"
IncludeFile "CkStringBuilder.pb"

Procedure ChilkatExample()

    success.i = 0

    ; To further clarify, see OAuth 2.0 Authorization Flow

    oauth2.i = CkOAuth2::ckCreate()
    If oauth2.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    ; Your Datev app should use "http://localhost" (no trailing forward slash) for the redirect URL.
    CkOAuth2::setCkListenPort(oauth2, 3017)

    ; 

    CkOAuth2::setCkAuthorizationEndpoint(oauth2, "https://login.datev.de/openidsandbox/authorize")
    CkOAuth2::setCkTokenEndpoint(oauth2, "https://sandbox-api.datev.de/token")

    ; Replace this with your actual client ID.
    CkOAuth2::setCkClientId(oauth2, "DATEV_CLIENT_ID")
    CkOAuth2::setCkClientSecret(oauth2, "DATEV_CLIENT_SECRET")

    CkOAuth2::setCkCodeChallenge(oauth2, 1)
    CkOAuth2::setCkCodeChallengeMethod(oauth2, "S256")

    CkOAuth2::setCkScope(oauth2, "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.
    url.s = CkOAuth2::ckStartAuth(oauth2)
    If CkOAuth2::ckLastMethodSuccess(oauth2) <> 1
        Debug CkOAuth2::ckLastErrorText(oauth2)
        CkOAuth2::ckDispose(oauth2)
        ProcedureReturn
    EndIf

    ; Launch the default browser on the system and navigate to the url.
    ; The LaunchBrowser method was added in Chilkat v10.1.2.
    success = CkOAuth2::ckLaunchBrowser(oauth2,url)
    If success = 0
        Debug CkOAuth2::ckLastErrorText(oauth2)
        CkOAuth2::ckDispose(oauth2)
        ProcedureReturn
    EndIf

    ; Wait for the interactive user to grant permission in the interactive browser session.
    ; We'll wait for a max of 90 seconds.
    numMsWaited.i = 0
    While (numMsWaited < 90000) AND (CkOAuth2::ckAuthFlowState(oauth2) < 3)
        CkOAuth2::ckSleepMs(oauth2,100)
        numMsWaited = numMsWaited + 100
    Wend

    ; 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 CkOAuth2::ckAuthFlowState(oauth2) < 3
        CkOAuth2::ckCancel(oauth2)
        Debug "No response from the browser!"
        CkOAuth2::ckDispose(oauth2)
        ProcedureReturn
    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 CkOAuth2::ckAuthFlowState(oauth2) = 5
        Debug "OAuth2 failed to complete."
        Debug CkOAuth2::ckFailureInfo(oauth2)
        CkOAuth2::ckDispose(oauth2)
        ProcedureReturn
    EndIf

    If CkOAuth2::ckAuthFlowState(oauth2) = 4
        Debug "OAuth2 authorization was denied."
        Debug CkOAuth2::ckAccessTokenResponse(oauth2)
        CkOAuth2::ckDispose(oauth2)
        ProcedureReturn
    EndIf

    If CkOAuth2::ckAuthFlowState(oauth2) <> 3
        Debug "Unexpected AuthFlowState:" + Str(CkOAuth2::ckAuthFlowState(oauth2))
        CkOAuth2::ckDispose(oauth2)
        ProcedureReturn
    EndIf

    ; Save the full JSON access token response to a file.
    sbJson.i = CkStringBuilder::ckCreate()
    If sbJson.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    CkStringBuilder::ckAppend(sbJson,CkOAuth2::ckAccessTokenResponse(oauth2))
    CkStringBuilder::ckWriteFile(sbJson,"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		
    ; }

    Debug "OAuth2 authorization granted!"
    Debug "Access Token = " + CkOAuth2::ckAccessToken(oauth2)


    CkOAuth2::ckDispose(oauth2)
    CkStringBuilder::ckDispose(sbJson)


    ProcedureReturn
EndProcedure