(SQL Server) Refresh HMRC OAuth2 Access Token

Demonstrates how to refresh an HMRC access token.

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.

    -- See Get HMRC Access Token 
    -- for sample code showing how to obtain a HMRC access token for desktop apps.

    -- It is assumed we previously obtained an OAuth2 access token for HMRC.

    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/hmrc.json'
    IF @success <> 1
      BEGIN

        PRINT 'Failed to load hmrc.json'
        EXEC @hr = sp_OADestroy @jsonToken
        RETURN
      END

    -- The access token JSON looks something like this:

    -- {
    --   "token_type": "Bearer",
    --   "scope": "user_impersonation",
    --   "expires_in": "3599",
    --   "ext_expires_in": "0",
    --   "expires_on": "1524783438",
    --   "not_before": "1524779538",
    --   "resource": "https://mydomain.api.crm.dynamics.com",
    --   "access_token": "...",
    --   "refresh_token": "...",
    --   "id_token": "..."
    -- }

    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://test-api.service.hmrc.gov.uk/oauth/token'

    -- Replace these with actual values.
    EXEC sp_OASetProperty @oauth2, 'ClientId', 'HMRC-CLIENT-ID'
    EXEC sp_OASetProperty @oauth2, 'ClientSecret', 'HMRC-CLIENT-SECRET'

    -- 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

    -- Load the access token response into the json object 
    EXEC sp_OAGetProperty @oauth2, 'AccessTokenResponse', @sTmp0 OUT
    EXEC sp_OAMethod @jsonToken, 'Load', @success OUT, @sTmp0

    -- If an "expires_on" member does not exist, then add the JSON member by
    -- getting the current system date/time and adding the "expires_in" seconds.
    -- This way we'll know when the token expires.
    EXEC sp_OAMethod @jsonToken, 'HasMember', @iTmp0 OUT, 'expires_on'
    IF @iTmp0 = 0
      BEGIN
        DECLARE @dtExpire int
        -- Use "Chilkat_9_5_0.CkDateTime" for versions of Chilkat < 10.0.0
        EXEC @hr = sp_OACreate 'Chilkat.CkDateTime', @dtExpire OUT

        EXEC sp_OAMethod @dtExpire, 'SetFromCurrentSystemTime', @success OUT
        EXEC sp_OAMethod @jsonToken, 'IntOf', @iTmp0 OUT, 'expires_in'
        EXEC sp_OAMethod @dtExpire, 'AddSeconds', @success OUT, @iTmp0
        EXEC sp_OAMethod @dtExpire, 'GetAsUnixTimeStr', @sTmp0 OUT, 0
        EXEC sp_OAMethod @jsonToken, 'AppendString', @success OUT, 'expires_on', @sTmp0
      END

    -- Save the new JSON access token response to a file.
    -- The access + refresh tokens contained in this JSON will be needed for the next refresh.
    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/hmrc.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 @dtExpire
    EXEC @hr = sp_OADestroy @sbJson


END
GO