SQL Server

Egyptian eReceipt OAuth2 Client Credentials

See more Egypt eReceipt Examples

Get an OAuth2 access token for the Egyptian eReceipt REST API using client credentials (no interactivity with a web browser required). SQL Server

-- 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)
    DECLARE @success int
    SELECT @success = 0

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

    DECLARE @http int
    EXEC @hr = sp_OACreate 'Chilkat.Http', @http OUT
    IF @hr <> 0
    BEGIN
        PRINT 'Failed to create ActiveX component'
        RETURN
    END

    -- Note: Any provider of a REST API, such as the Egyptian government in this case, can make life 
    -- much easier for developers by providing one or more of the following in the API documentation:
    -- 
    -- 1) A sample CURL statement for each API call.
    -- 2) A Postman collection, or Swagger/OpenAPI specification file.
    -- 3) A sample of a raw HTTP request and response for each API call.
    -- 
    -- The sample CURL statements or raw HTTP request/responses do not need to comprehensively show all 
    -- possible options.  Providing a sample allows one to quickly make a successful API call.
    -- It also allows for code generation directly from the CURL, Postman collection, or raw request/response,
    -- and it tends to answer all questions about the format/structure of a request that, suprisingly,
    -- remain ambiguous or not obvious in other forms of documentation.

    DECLARE @req int
    EXEC @hr = sp_OACreate 'Chilkat.HttpRequest', @req OUT

    EXEC sp_OAMethod @req, 'AddParam', NULL, 'grant_type', 'client_credentials'
    -- Use your actual client ID and client secret...
    EXEC sp_OAMethod @req, 'AddParam', NULL, 'client_id', 'd0394a9f-0607-40de-a978-2d3eb8375b04'
    EXEC sp_OAMethod @req, 'AddParam', NULL, 'client_secret', '6d62315e-d65a-4e41-9112-4195ea834edf'

    EXEC sp_OAMethod @req, 'AddHeader', NULL, 'posserial', '1234567899'
    EXEC sp_OAMethod @req, 'AddHeader', NULL, 'pososversion', 'os'
    EXEC sp_OAMethod @req, 'AddHeader', NULL, 'posmodelframework', '1'
    EXEC sp_OAMethod @req, 'AddHeader', NULL, 'presharedkey', '03ac674216f3e1...'

    -- When writing this example, the documentation at https://sdk.invoicing.eta.gov.eg/ereceiptapi/01-authenticate-pos/
    -- shows us the HTTP verb and path (POST /connect/token), however,
    -- we don't see the actual domain where the request is to be sent.
    -- What are the endpoints???
    -- It took some searching, but we found some endpoints here:  https://sdk.invoicing.eta.gov.eg/faq/
    -- It's not immediately apparent which endpoint is to be used with a given API call.
    -- Why not just include the endpoint in the documentation for each REST API call?
    -- Endpoints are literally the #1 thing that needs to be known.
    -- They can't just be buried in a FAQ.  They should be up-front and obvious.
    -- 
    -- So.. we're guessing the endpoint is likely "https://invoicing.eta.gov.eg/connect/token"
    EXEC sp_OASetProperty @req, 'HttpVerb', 'POST'
    EXEC sp_OASetProperty @req, 'ContentType', 'application/x-www-form-urlencoded'

    DECLARE @resp int
    EXEC @hr = sp_OACreate 'Chilkat.HttpResponse', @resp OUT

    EXEC sp_OAMethod @http, 'HttpReq', @success OUT, 'https://invoicing.eta.gov.eg/connect/token', @req, @resp
    IF @success = 0
      BEGIN
        EXEC sp_OAGetProperty @http, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @http
        EXEC @hr = sp_OADestroy @req
        EXEC @hr = sp_OADestroy @resp
        RETURN
      END

    DECLARE @sbResponseBody int
    EXEC @hr = sp_OACreate 'Chilkat.StringBuilder', @sbResponseBody OUT

    EXEC sp_OAMethod @resp, 'GetBodySb', @success OUT, @sbResponseBody

    DECLARE @jResp int
    EXEC @hr = sp_OACreate 'Chilkat.JsonObject', @jResp OUT

    EXEC sp_OAMethod @jResp, 'LoadSb', @success OUT, @sbResponseBody
    EXEC sp_OASetProperty @jResp, 'EmitCompact', 0


    PRINT 'Response Body:'
    EXEC sp_OAMethod @jResp, 'Emit', @sTmp0 OUT
    PRINT @sTmp0

    DECLARE @respStatusCode int
    EXEC sp_OAGetProperty @resp, 'StatusCode', @respStatusCode OUT

    PRINT 'Response Status Code = ' + @respStatusCode
    IF @respStatusCode >= 400
      BEGIN

        PRINT 'Response Header:'
        EXEC sp_OAGetProperty @resp, 'Header', @sTmp0 OUT
        PRINT @sTmp0

        PRINT 'Failed.'
        EXEC @hr = sp_OADestroy @http
        EXEC @hr = sp_OADestroy @req
        EXEC @hr = sp_OADestroy @resp
        EXEC @hr = sp_OADestroy @sbResponseBody
        EXEC @hr = sp_OADestroy @jResp
        RETURN
      END

    -- If successful, the OAuth2 access token JSON looks like this:

    -- {
    --   "token_type": "Bearer",
    --   "access_token": "eyJraW......R2sbqrY",
    --   "expires_in": "3600",
    --   "scope": "..."
    -- }

    DECLARE @token_type nvarchar(4000)
    EXEC sp_OAMethod @jResp, 'StringOf', @token_type OUT, 'token_type'
    DECLARE @access_token nvarchar(4000)
    EXEC sp_OAMethod @jResp, 'StringOf', @access_token OUT, 'access_token'
    DECLARE @expires_in nvarchar(4000)
    EXEC sp_OAMethod @jResp, 'StringOf', @expires_in OUT, 'expires_in'
    DECLARE @scope nvarchar(4000)
    EXEC sp_OAMethod @jResp, 'StringOf', @scope OUT, 'scope'

    EXEC @hr = sp_OADestroy @http
    EXEC @hr = sp_OADestroy @req
    EXEC @hr = sp_OADestroy @resp
    EXEC @hr = sp_OADestroy @sbResponseBody
    EXEC @hr = sp_OADestroy @jResp


END
GO