(SQL Server) Refresh a Xero OAuth2 Access Token

Refreshes a Xero OAuth2 access token. When an access token expires (after 1 hour), you will received a 401 status code indicating failure. When that happens, your application can run this code to refresh the access token, and then retry the request using the new access token. Refreshing an access token does not need user interaction (i.e. does not need to display a browser to have the user interactive authorize access).

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
    -- 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.

    -- It is assumed we previously obtained an OAuth2 access token.
    -- This example loads the JSON access token file 
    -- saved by this example: Get Xero OAuth2 Access Token

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

    DECLARE @success int
    EXEC sp_OAMethod @jsonToken, 'LoadFile', @success OUT, 'qa_data/tokens/xero-access-token.json'
    IF @success <> 1
      BEGIN

        PRINT 'Failed to load xero-access-token.json'
        EXEC @hr = sp_OADestroy @jsonToken
        RETURN
      END

    -- The access token JSON looks like this:

    -- {
    --   "id_token": "eyJhbGci...dqRs3MctS_g",
    --   "access_token": "eyJhbGci...sUoAhoQ",
    --   "expires_in": 1800,
    --   "token_type": "Bearer",
    --   "refresh_token": "2f77b...bfc2ee16f",
    --   "scope": "openid profile email accounting.transactions accounting.settings payroll.employees offline_access"
    -- }

    DECLARE @oauth2 int
    -- Use "Chilkat_9_5_0.OAuth2" for versions of Chilkat < 10.0.0
    EXEC @hr = sp_OACreate 'Chilkat.OAuth2', @oauth2 OUT

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

    -- Replace these with actual values.
    EXEC sp_OASetProperty @oauth2, 'ClientId', 'XERO_APP_OAUTH2_CLIENT_ID'
    EXEC sp_OASetProperty @oauth2, 'ClientSecret', 'XERO_APP_OAUTH2_CLIENT_SECRET'
    EXEC sp_OASetProperty @oauth2, 'UseBasicAuth', 1

    -- Get the "refresh_token"
    EXEC sp_OAMethod @jsonToken, 'StringOf', @sTmp0 OUT, 'refresh_token'
    EXEC sp_OASetProperty @oauth2, 'RefreshToken', @sTmp0

    -- Send the HTTP POST to refresh the access token..
    EXEC sp_OAMethod @oauth2, 'RefreshAccessToken', @success OUT
    IF @success <> 1
      BEGIN
        EXEC sp_OAGetProperty @oauth2, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @jsonToken
        EXEC @hr = sp_OADestroy @oauth2
        RETURN
      END

    EXEC sp_OAGetProperty @oauth2, 'AccessTokenResponse', @sTmp0 OUT
    PRINT @sTmp0

    -- The response contains a new access token and refresh token.
    -- Update the JSON and re-save to the token file.
    EXEC sp_OAGetProperty @oauth2, 'AccessToken', @sTmp0 OUT
    EXEC sp_OAMethod @jsonToken, 'UpdateString', @success OUT, 'access_token', @sTmp0
    EXEC sp_OAGetProperty @oauth2, 'RefreshToken', @sTmp0 OUT
    EXEC sp_OAMethod @jsonToken, 'UpdateString', @success OUT, 'refresh_token', @sTmp0

    -- Save the new 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_OASetProperty @jsonToken, 'EmitCompact', 0
    EXEC sp_OAMethod @jsonToken, 'EmitSb', @success OUT, @sbJson
    EXEC sp_OAMethod @sbJson, 'WriteFile', @success OUT, 'qa_data/tokens/xero-access-token.json', 'utf-8', 0


    PRINT 'OAuth2 authorization granted!'

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

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


END
GO