(Visual FoxPro) Adobe Sign OAuth2 Access Token

Demonstrates how to get an Adobe Sign OAuth2 access token from a desktop application or script.

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

LOCAL loOauth2
LOCAL lnSuccess
LOCAL lcUrl
LOCAL lnNumMsWaited
LOCAL loSbJson

* It 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')

* The Adobe Sign OAuth2 requires an "https" callback URL.  This means the "http://localhost:<portNumber>/" is not possible.
* For a desktop app, you must provide a script on your web server to redirect to "http://localhost:<portNumber>/"
* It can be written in C#, PHP, or whatever desired.  It must include the query string in the redirection.
* For example, in PHP your script would look like this:

* <?php
*   header( 'Location: http://localhost:3017?' . $_SERVER['QUERY_STRING'] );
* ?>

loOauth2.AppCallbackUrl = "https://yourwebserver.com/OAuth2.php"
loOauth2.ListenPort = 3017

loOauth2.AuthorizationEndpoint = "https://secure.na2.echosign.com/public/oauth"
loOauth2.TokenEndpoint = "https://api.na2.echosign.com/oauth/token"

* Replace these with actual values.
loOauth2.ClientId = "MY_CLIENT_ID"
loOauth2.ClientSecret = "MY_CLIENT_SECRET"
loOauth2.CodeChallenge = 0

* Indicate the desired access by listing scopes.
loOauth2.Scope = "user_read agreement_read workflow_read"

* 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

? "url = " + lcUrl

* 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 Adobe Sign 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 60 seconds.
lnNumMsWaited = 0
DO WHILE (lnNumMsWaited < 60000) AND (loOauth2.AuthFlowState < 3)
    loOauth2.SleepMs(100)
    lnNumMsWaited = lnNumMsWaited + 100
ENDDO

* If there was no response from the browser within 60 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.
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.StringBuilder')
loSbJson = CreateObject('Chilkat.StringBuilder')
loSbJson.Append(loOauth2.AccessTokenResponse)
loSbJson.WriteFile("qa_data/tokens/adobe-sign-access-token.json","utf-8",0)

* The full JSON received looks like this:
* {
*   "access_token": "3AAABL ... YCpUu",
*   "refresh_token": "3AAABL ... tpDs0*",
*   "token_type": "Bearer",
*   "expires_in": 3600
* }

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

RELEASE loOauth2
RELEASE loSbJson