DataFlex

WebSocket Connect

See more WebSocket Examples

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.) DataFlex

Use ChilkatAx-win32.pkg

Procedure Test
    Boolean iSuccess
    Variant vRest
    Handle hoRest
    Handle hoWs
    String sResponseBody
    Integer iStatusCode
    String sTemp1
    Boolean bTemp1

    Move False To iSuccess

    // 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.
    // 

    Get Create (RefClass(cComChilkatRest)) To hoRest
    If (Not(IsComObjectCreated(hoRest))) Begin
        Send CreateComObject of hoRest
    End
    Get ComConnect Of hoRest "someserver.com" 80 False False To iSuccess
    If (iSuccess <> True) Begin
        Get ComLastErrorText Of hoRest To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Get Create (RefClass(cComChilkatWebSocket)) To hoWs
    If (Not(IsComObjectCreated(hoWs))) Begin
        Send CreateComObject of hoWs
    End

    // Tell the WebSocket to use this connection.
    Get pvComObject of hoRest to vRest
    Get ComUseConnection Of hoWs vRest To iSuccess
    If (iSuccess <> True) Begin
        Get ComLastErrorText Of hoWs To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // Add the standard WebSocket open handshake headers that will be needed.
    // (This adds the required HTTP request headers to the rest object.)
    Get ComAddClientHeaders Of hoWs To iSuccess

    // Add any additional headers that might be desired.
    // Two common WebSocketSpecific headers are "Sec-WebSocket-Protocol" and "Origin".
    Get ComAddHeader Of hoRest "Sec-WebSocket-Protocol" "x-something" To iSuccess
    Get ComAddHeader Of hoRest "Origin" "http://someserver.com" To iSuccess

    // Do the open handshake.
    Get ComFullRequestNoBody Of hoRest "GET" "/something" To sResponseBody
    Get ComLastMethodSuccess Of hoRest To bTemp1
    If (bTemp1 <> True) Begin
        Get ComLastErrorText Of hoRest To sTemp1
        Showln sTemp1
        Procedure_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..)
    Get ComResponseStatusCode Of hoRest To iStatusCode
    Showln "Response status code: " iStatusCode

    If (iStatusCode <> 101) Begin
        Showln sResponseBody
        Showln "-- Failed because of unexpected response status code."
        Procedure_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. 
    Get ComValidateServerHandshake Of hoWs To iSuccess
    If (iSuccess <> True) Begin
        Get ComLastErrorText Of hoWs To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Showln "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...)


End_Procedure