(Visual FoxPro) Docusign Request Impersonation Consent

Demonstrates how to obtain impersonation consent from a Docusign individual user. This is one way of getting consent prior to using the JWT (JSON Web Token) grant flow to obtain access tokens. See the Docusign documentation for Obtaining Consent and JSON Web Token (JWT) Grant for more information.

Important: This example requires that you add a line of code (or a few lines of code) to launch a web browser that navigates to the URL returned by the StartAuth method.

For more information, see https://developers.docusign.com/esign-rest-api/guides/authentication/oauth2-jsonwebtoken

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

LOCAL loOauth2
LOCAL lnSuccess
LOCAL lcUrl
LOCAL lnNumMsWaited
LOCAL loJson
LOCAL loFac

* This example requires the Chilkat API to have been previously unlocked.
* See Global Unlock Sample for sample code.

* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.OAuth2')
loOauth2 = CreateObject('Chilkat.OAuth2')

* This should be the port in the localhost Redirect URI for your app defined in the Docusign developer portal.  
* The Redirect URI would look like "http://localhost:3017/" if the port number is 3017.
loOauth2.ListenPort = 3017

* For the developer sandbox environment, the authorization endpoint is https://account-d.docusign.com/oauth/auth
* For the production platform, the authorization endpoint is https://account.docusign.com/oauth/auth
loOauth2.AuthorizationEndpoint = "https://account-d.docusign.com/oauth/auth"
loOauth2.TokenEndpoint = "https://account-d.docusign.com/oauth/token"

* Replace these with actual values.
* The client ID is also known as the "integration key" in Docusign.
loOauth2.ClientId = "MY_DOCUSIGN_CLIENT_ID"
* This is your secret key for the authorization code grant.
loOauth2.ClientSecret = "MY_DOCUSIGN_CLIENT_SECRET"

loOauth2.Scope = "signature impersonation"

* Begin the OAuth2 three-legged 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

* 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 Microsoft account owner would interactively accept or deny the authorization request.

* 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.
lnNumMsWaited = 0
DO WHILE (lnNumMsWaited < 30000) AND (loOauth2.AuthFlowState < 3)
    loOauth2.SleepMs(100)
    lnNumMsWaited = lnNumMsWaited + 100
ENDDO

* 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 (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

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

* Get the full JSON response:
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.JsonObject')
loJson = CreateObject('Chilkat.JsonObject')
loJson.Load(loOauth2.AccessTokenResponse)
loJson.EmitCompact = 0
? loJson.Emit()

* The JSON response looks like this:

* Note: It doesn't seem like the access_token obtained here is actually used.
* My guess is that the act of getting this access token persists the knowledge that the
* DocuSign user account has granted access to the application.  The application only needs
* to send a valid JWT to prove it's identity and get an access token (JSON Web Token Grant (JWT))
* {
*   "access_token": "eyJ0eXA....YQyig",
*   "token_type": "Bearer",
*   "refresh_token": "eyJ0eXA....auE3eHKg",
*   "expires_in": 28800
* }

* Save the JSON to a file for future requests.
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.FileAccess')
loFac = CreateObject('Chilkat.FileAccess')
loFac.WriteEntireTextFile("qa_data/tokens/docusignImpersonation.json",loJson.Emit(),"utf-8",0)

RELEASE loOauth2
RELEASE loJson
RELEASE loFac