(SQL Server) Get a Xero OAuth2 Access Token via PKCE

See more Xero Examples

Gets a Xero OAuth2 access token via PKCE.

For more information, see https://github.com/XeroAPI/Xero-Postman-Tutorial-PKCE-Edition

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

-- Important: See this note about string length limitations for strings returned by sp_OAMethod calls.
--
CREATE PROCEDURE ChilkatSample
AS
BEGIN
    DECLARE @hr int
    DECLARE @iTmp0 int
    -- Important: Do not use nvarchar(max).  See the warning about using nvarchar(max).
    DECLARE @sTmp0 nvarchar(4000)
    -- This example requires the Chilkat API to have been previously unlocked.
    -- See Global Unlock Sample for sample code.

    DECLARE @oauth2 int
    -- Use "Chilkat_9_5_0.OAuth2" for versions of Chilkat < 10.0.0
    EXEC @hr = sp_OACreate 'Chilkat.OAuth2', @oauth2 OUT
    IF @hr <> 0
    BEGIN
        PRINT 'Failed to create ActiveX component'
        RETURN
    END

    DECLARE @success int

    -- For Xero OAuth2, set the listen port equal to the port used
    -- in the Authorized Redirect URL for the Client ID.
    -- For example, in this case the Authorized Redirect URL would be http://localhost:55568/
    -- (The final "/" char is important to include in your Authorized Redirect URL in the Xero application settings in the Xero developer portal.)
    -- Your app should choose a port not likely not used by any other application.
    -- See Xero OAuth2 for Desktop Apps for more information.
    EXEC sp_OASetProperty @oauth2, 'ListenPort', 55568

    EXEC sp_OASetProperty @oauth2, 'AuthorizationEndpoint', 'https://login.xero.com/identity/connect/authorize'
    EXEC sp_OASetProperty @oauth2, 'TokenEndpoint', 'https://identity.xero.com/connect/token'

    -- Replace this with your actual Client ID.
    EXEC sp_OASetProperty @oauth2, 'ClientId', 'XERO_APP_OAUTH2_CLIENT_ID'

    -- To use PKCE, enable code challenge and set the code challenge method to "S256".
    EXEC sp_OASetProperty @oauth2, 'CodeChallenge', 1
    EXEC sp_OASetProperty @oauth2, 'CodeChallengeMethod', 'S256'

    -- See https://developer.xero.com/documentation/oauth2/scopes for a complete list of scopes.
    -- You will need to change the scopes depending on what access is needed..
    EXEC sp_OASetProperty @oauth2, 'Scope', 'openid profile email accounting.transactions accounting.attachments accounting.settings payroll.employees offline_access'

    -- Begin the OAuth2 three-legged flow.  This returns a URL that should be loaded in a browser.
    DECLARE @url nvarchar(4000)
    EXEC sp_OAMethod @oauth2, 'StartAuth', @url OUT
    EXEC sp_OAGetProperty @oauth2, 'LastMethodSuccess', @iTmp0 OUT
    IF @iTmp0 <> 1
      BEGIN
        EXEC sp_OAGetProperty @oauth2, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @oauth2
        RETURN
      END


    PRINT 'URL: ' + @url

    -- 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        
    -- in dBASE: run(false, 'rundll32 url.dll,FileProtocolHandler "' + lcUrl + '"')
    -- The Google 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...
    -- System.Diagnostics.Process.Start(url);

    -- Now wait for the authorization.
    -- We'll wait for a max of 60 seconds.
    DECLARE @numMsWaited int
    SELECT @numMsWaited = 0
    EXEC sp_OAGetProperty @oauth2, 'AuthFlowState', @iTmp0 OUT
    WHILE (@numMsWaited < 60000) and (@iTmp0 < 3)
      BEGIN
        EXEC sp_OAMethod @oauth2, 'SleepMs', NULL, 100
        SELECT @numMsWaited = @numMsWaited + 100
      END

    -- 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.
    EXEC sp_OAGetProperty @oauth2, 'AuthFlowState', @iTmp0 OUT
    IF @iTmp0 < 3
      BEGIN
        EXEC sp_OAMethod @oauth2, 'Cancel', @success OUT

        PRINT 'No response from the browser!'
        EXEC @hr = sp_OADestroy @oauth2
        RETURN
      END

    -- 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.
    EXEC sp_OAGetProperty @oauth2, 'AuthFlowState', @iTmp0 OUT
    IF @iTmp0 = 5
      BEGIN

        PRINT 'OAuth2 failed to complete.'
        EXEC sp_OAGetProperty @oauth2, 'FailureInfo', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @oauth2
        RETURN
      END

    EXEC sp_OAGetProperty @oauth2, 'AuthFlowState', @iTmp0 OUT
    IF @iTmp0 = 4
      BEGIN

        PRINT 'OAuth2 authorization was denied.'
        EXEC sp_OAGetProperty @oauth2, 'AccessTokenResponse', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @oauth2
        RETURN
      END

    EXEC sp_OAGetProperty @oauth2, 'AuthFlowState', @iTmp0 OUT
    IF @iTmp0 <> 3
      BEGIN

        EXEC sp_OAGetProperty @oauth2, 'AuthFlowState', @iTmp0 OUT
        PRINT 'Unexpected AuthFlowState:' + @iTmp0
        EXEC @hr = sp_OADestroy @oauth2
        RETURN
      END

    -- Save the full JSON access token response to a file.
    DECLARE @sbJson int
    -- Use "Chilkat_9_5_0.StringBuilder" for versions of Chilkat < 10.0.0
    EXEC @hr = sp_OACreate 'Chilkat.StringBuilder', @sbJson OUT

    EXEC sp_OAGetProperty @oauth2, 'AccessTokenResponse', @sTmp0 OUT
    EXEC sp_OAMethod @sbJson, 'Append', @success OUT, @sTmp0
    EXEC sp_OAMethod @sbJson, 'WriteFile', @success OUT, 'qa_data/tokens/xero-access-token.json', 'utf-8', 0

    -- The saved JSON response looks like this:

    -- 	{
    -- 	 "access_token": "...",
    -- 	 "token_type": "Bearer",
    -- 	 "expires_in": 3600,
    -- 	 "refresh_token": "..."
    -- 	}
    -- 

    PRINT 'OAuth2 authorization granted!'

    EXEC sp_OAGetProperty @oauth2, 'AccessToken', @sTmp0 OUT
    PRINT 'Access Token = ' + @sTmp0

    EXEC @hr = sp_OADestroy @oauth2
    EXEC @hr = sp_OADestroy @sbJson


END
GO