(SQL Server) WebSocket Connect

Demonstrates how to establish a WebSocket connection. Once the connection is established, messages may be sent back-and-forth. Messages are sent in frames, where the last frame in the message is indicated by a "final" bit. A frame constitutes the entire message if the first frame sent has the "final" bit sent. (In most cases, you'll probably be sending single-frame messages.)

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.

    -- --------------------------------------------------
    -- A WebSocket connection begins life as an HTTP GET request containing a few special header fields,
    -- such as "Upgrade: websocket".   

    -- Your application will use the Chilkat Rest class to send the initial HTTP GET.  This allows you
    -- to use the full capability of the Chilkat Rest class to customize the GET for any particular situation.
    -- For example:
    -- 
    --   - If custom HTTP request header fields must be added.
    --   - If authentication is required, such as OAuth2, OAuth1, Basic HTTP Auth, etc.
    --   - If HTTPS, SSH Tunneling, Proxies (HTTP or SOCKS), or other advanced connection or TLS features are required.
    -- 

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

    DECLARE @success int
    EXEC sp_OAMethod @rest, 'Connect', @success OUT, 'someserver.com', 80, 0, 0
    IF @success <> 1
      BEGIN
        EXEC sp_OAGetProperty @rest, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @rest
        RETURN
      END

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

    -- Tell the WebSocket to use this connection.
    EXEC sp_OAMethod @ws, 'UseConnection', @success OUT, @rest
    IF @success <> 1
      BEGIN
        EXEC sp_OAGetProperty @ws, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @rest
        EXEC @hr = sp_OADestroy @ws
        RETURN
      END

    -- Add the standard WebSocket open handshake headers that will be needed.
    -- (This adds the required HTTP request headers to the rest object.)
    EXEC sp_OAMethod @ws, 'AddClientHeaders', @success OUT

    -- Add any additional headers that might be desired.
    -- Two common WebSocketSpecific headers are "Sec-WebSocket-Protocol" and "Origin".
    EXEC sp_OAMethod @rest, 'AddHeader', @success OUT, 'Sec-WebSocket-Protocol', 'x-something'
    EXEC sp_OAMethod @rest, 'AddHeader', @success OUT, 'Origin', 'http://someserver.com'

    -- Do the open handshake.
    DECLARE @responseBody nvarchar(4000)
    EXEC sp_OAMethod @rest, 'FullRequestNoBody', @responseBody OUT, 'GET', '/something'
    EXEC sp_OAGetProperty @rest, 'LastMethodSuccess', @iTmp0 OUT
    IF @iTmp0 <> 1
      BEGIN
        EXEC sp_OAGetProperty @rest, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @rest
        EXEC @hr = sp_OADestroy @ws
        RETURN
      END

    -- If successful, the HTTP response status code should be 101,
    -- and the response body will be empty. (If it failed, we'll have a look
    -- at the response body..)
    DECLARE @statusCode int
    EXEC sp_OAGetProperty @rest, 'ResponseStatusCode', @statusCode OUT

    PRINT 'Response status code: ' + @statusCode

    IF @statusCode <> 101
      BEGIN

        PRINT @responseBody

        PRINT '-- Failed because of unexpected response status code.'
        EXEC @hr = sp_OADestroy @rest
        EXEC @hr = sp_OADestroy @ws
        RETURN
      END

    -- We have the expected 101 response, so let's now validate the 
    -- contents of the response, such as the value sent by the server in the
    -- Sec-WebSocket-Accept header. 
    EXEC sp_OAMethod @ws, 'ValidateServerHandshake', @success OUT
    IF @success <> 1
      BEGIN
        EXEC sp_OAGetProperty @ws, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @rest
        EXEC @hr = sp_OADestroy @ws
        RETURN
      END


    PRINT 'WebSocket connection successful.'

    -- The application may now begin sending and receiving frames on the WebSocket connection.
    -- (At this point, we're done with the rest object...)

    EXEC @hr = sp_OADestroy @rest
    EXEC @hr = sp_OADestroy @ws


END
GO