Xbase++ Requires Chilkat v10.1.2+

Twinfield OAuth2 for Desktop App or Script

See more OAuth2 Examples

Demonstrates how to get a Twinfield OAuth2 access token from a desktop application or script. Xbase++

LOCAL nSuccess
LOCAL oOauth2
LOCAL cUrl
LOCAL nNumMsWaited
LOCAL oJson
LOCAL oFac

nSuccess := 0

//  For more information about the OAuth2, see OAuth 2.0 Authorization Flow

oOauth2 := CreateObject("Chilkat.OAuth2")

//  This should be the port in the localhost callback URL for your app.  
//  The callback URL would look like "http://localhost:3017/" if the port number is 3017.
oOauth2:ListenPort := 3017

oOauth2:AuthorizationEndpoint := "https://login.twinfield.com/auth/authentication/connect/authorize"
oOauth2:TokenEndpoint := "https://login.twinfield.com/auth/authentication/connect/token"

//  Replace these with actual values.
oOauth2:ClientId := "CLIENT_ID"
oOauth2:ClientSecret := "CLIENT_SECRET"

oOauth2:Scope := "openid twf.user twf.organisation twf.organisationUser offline_access"

oOauth2:CodeChallenge := 1
oOauth2:CodeChallengeMethod := "S256"

//  Twinfield requires that the request to exchange the authorization code for a token must be a GET.
//  (In most cases, OAuth2 is implemented where the exchange for token HTTP request is a POST.)
//  Note: The exchange-for-token happens within Chilkat in a background thread.  After the user interactively 
//  accepts or denies authorization, the browser receives the response and redirects to localhost:<port>,
//  where Chilkat is waiting on a background thread to receive the redirect, process it, and then send the HTTP request
//  to exchange the code for a token.  This happens internally while your code below is waiting for the authorization..)
oOauth2:UncommonOptions := "EXCHANGE_CODE_FOR_TOKEN_USING_GET"

//  Begin the OAuth2 Authorization code flow.  This returns a URL that should be loaded in a browser.
cUrl := oOauth2:StartAuth()
IF (oOauth2:LastMethodSuccess != 1)
    ? oOauth2:LastErrorText
    oOauth2:destroy()
    RETURN
ENDIF

? "url = " + cUrl

//  Launch the default browser on the system and navigate to the url.
//  The LaunchBrowser method was added in Chilkat v10.1.2.
nSuccess := oOauth2:LaunchBrowser(cUrl)
IF (nSuccess == 0)
    ? oOauth2:LastErrorText
    oOauth2:destroy()
    RETURN
ENDIF

//  Wait for the user to approve or deny authorization in the browser.
nNumMsWaited := 0
DO WHILE (nNumMsWaited < 90000) .AND. (oOauth2:AuthFlowState < 3)
    oOauth2:SleepMs(100)
    nNumMsWaited := nNumMsWaited + 100
ENDDO

//  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 (oOauth2:AuthFlowState < 3)
    oOauth2:Cancel()
    ? "No response from the browser!"
    oOauth2:destroy()
    RETURN
ENDIF

//  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 (oOauth2:AuthFlowState == 5)
    ? "OAuth2 failed to complete."
    ? oOauth2:FailureInfo
    oOauth2:destroy()
    RETURN
ENDIF

IF (oOauth2:AuthFlowState == 4)
    ? "OAuth2 authorization was denied."
    ? oOauth2:AccessTokenResponse
    oOauth2:destroy()
    RETURN
ENDIF

IF (oOauth2:AuthFlowState != 3)
    ? "Unexpected AuthFlowState:" + Str(oOauth2:AuthFlowState)
    oOauth2:destroy()
    RETURN
ENDIF

? "OAuth2 authorization granted!"
? "Access Token = " + oOauth2:AccessToken

//  Get the full JSON response:
oJson := CreateObject("Chilkat.JsonObject")
oJson:Load(oOauth2:AccessTokenResponse)
oJson:EmitCompact := 0

//  The JSON response looks like this:

? oJson:Emit()

//  Save the JSON to a file for future requests.
oFac := CreateObject("Chilkat.FileAccess")
oFac:WriteEntireTextFile("qa_data/tokens/twinfield.json", oJson:Emit(), "utf-8", 0)

oOauth2:destroy()
oJson:destroy()
oFac:destroy()