Connecting to the API

1. Open a TCP socket.
2. Authentication: Login by sending a CSTA StartApplicationSession request in XML format (as a string) to the socket.
3. CSTA request, responses and CSTA events are received as strings from the TCP socket. You need to split up the received text into XML document strings and then deserialized into a typed object if needed.

tip

The TCP client support XML requests, responses and events. They follow the CSTA format in the ECMA-323 CSTA Standard.

.NET Sample Client

This sample client is written in C# .NET using the NetCoreServer library available at nuget.

It provides the basis for setting up a TCP client, so you can begin communication with the Uni-tel CSTA API via TCP.

public class TcpClient : NetCoreServer.TcpClient
{
    private const string MESSAGE_TERMINATOR = "\0";

    private readonly Action<object> _newMessageFunc;
    private readonly Serializer _serializer;
    private string _dataReceived = string.Empty;

    public TcpClient(Action<object> newMessageFunc, string address, int port) : base(address, port)
    {
        _newMessageFunc = newMessageFunc;
        _serializer = new Serializer();
    }

    public void SendAsync<T>(T message)
    {
        Console.WriteLine($"Sending {message.GetType()} message ");

        base.SendAsync(_serializer.Serialize(message) + MESSAGE_TERMINATOR);
    }

    protected override void OnConnected()
    {
        Console.WriteLine($"TcpClient connected");

        ReceiveAsync();

        base.OnConnected();
    }

    protected override void OnDisconnected()
    {
        Console.WriteLine($"TcpClient disconnected");

        base.OnDisconnected();
    }

    protected override void OnReceived(byte[] buffer, long offset, long size)
    {
        var chunk = Encoding.UTF8.GetString(buffer, (int)offset, (int)size);
        _dataReceived += chunk;

        while (_dataReceived.Contains(MESSAGE_TERMINATOR))
        {
            var index = _dataReceived.IndexOf(MESSAGE_TERMINATOR, StringComparison.Ordinal);
            var message = _dataReceived.Substring(0, index);
            _dataReceived = _dataReceived.Substring(index + 1);

            try
            {
                var convertedMessage = _serializer.Deserialize(message);
                _newMessageFunc(convertedMessage);
            }
            catch (Exception ex)
            {
                Console.WriteLine($"Invalid XML document? Exception: {ex.Message}. XML = {message}");
            }
        }
    }

    protected override void OnError(SocketError error)
    {
        Console.WriteLine($"TCP client returned error code: '{error}'");
    }
}