/// <summary>Creates a SerialDeviceEndpoint from a valid connection string.</summary>
/// <param name="connectionString">The connection string.</param>
/// <returns>A populated <see cref="SerialDeviceEndpoint" />.</returns>
/// <exception cref="ArgumentException"></exception>
/// <remarks>
/// <para>
/// Valid connection strings must match the following regular expression grammar:
/// <code lang="regex">
/// ^((COM|com)\d{1,3})(:((\d{3,7})(,(None|Even|Odd|Mark|Space))?(,(7|8))?(,(Zero|OnePointFive|One|Two))?(,(nodtr|dtr))?(,(norts|rts))?(,(None|XOnXOff|RequestToSend|RequestToSendXOnXOff))?)?)?$
/// </code>
/// </para>
/// <para>
/// Since that is a rather unfriendly expression to human eyes, one way to determine correct
/// connection string syntax is to create a specimen endpoint, passing in the required
/// configuration as constructor parameters. Then, write the object to an output stream. The
/// ToString method will write out a syntactically correct connection string. There are many
/// ways to accomplish this. For example, you can use the C# Interactive window in Visual
/// Studio, write a unit test, use Windows PowerShell or an utility such as LINQPad. In
/// LINQPad, the following fragment will suffice:
/// <code lang="csharp">
/// var endpoint = new SerialDeviceEndpoint("COM1"); // Pass in whatever parameters you need
/// endpoint.Dump();
/// </code>
/// </para>
/// <para>
/// It is probably best to avoid creating connection strings directly as this will tend to be
/// error prone, especially if it is from user-supplied input. Instead, create a user interface
/// that gathers all of the serial parameters from the user. For an ASCOM driver, this will
/// likely be part of the Setup Dialog. Save all the user-supplied data in your settings. Then
/// generate a connection string by creating a <see cref="SerialDeviceEndpoint" />, passing the
/// user settings in as constructor parameters. Finally, use <see cref="ToString" /> or the
/// <see cref="DeviceEndpoint.DeviceAddress" /> property to retrieve the corresponding
/// connection string. The connection string can either be saved along with user settings and
/// used 'as-is' in the next session, or it can be dynamically regenerated on demand using the
/// above technique - the choice is yours. It is also up to you whether or not you decide to
/// make the connection string visible to the user.
/// </para>
/// </remarks>
public static SerialDeviceEndpoint FromConnectionString(string connectionString)
{
Contract.Requires(!string.IsNullOrWhiteSpace(connectionString));
Contract.Ensures(Contract.Result <DeviceEndpoint>() != null);
var matches = SerialRegex.Match(connectionString);
if (!matches.Success)
{
throw new ArgumentException(
"Not a valid serial connection string; Example: COM127:9600,None,8,One,dtr,norts",
nameof(connectionString));
}
var portName = matches.Groups["PortName"].Value;
var baud = CaptureGroupOrDefault(matches, "Baud", 9600);
var parity = CaptureGroupOrDefault(matches, "Parity", Parity.None);
var databits = CaptureGroupOrDefault(matches, "DataBits", 8);
var stopbits = CaptureGroupOrDefault(matches, "StopBits", StopBits.One);
var assertDtr = CaptureGroupOrDefault(matches, "DTR", "dtr")
.Equals("dtr", StringComparison.InvariantCultureIgnoreCase);
var assertRts = CaptureGroupOrDefault(matches, "RTS", "rts")
.Equals("rts", StringComparison.InvariantCultureIgnoreCase);
var handshake = CaptureGroupOrDefault(matches, "Handshake", Handshake.None);
var endpoint = new SerialDeviceEndpoint(portName, baud, parity, databits, stopbits, assertDtr, assertRts,
handshake);
return(endpoint);
}
/// <summary>Initializes a new instance of the <see cref="SerialCommunicationChannel" /> class.</summary>
/// <param name="endpoint">The device endpoint.</param>
/// <param name="port">The port.</param>
/// <exception cref="System.ArgumentException">Expected a SerialDeviceEndpoint</exception>
public SerialCommunicationChannel(DeviceEndpoint endpoint, ISerialPort port = null)
{
if (!(endpoint is SerialDeviceEndpoint))
{
throw new ArgumentException("Expected a SerialDeviceEndpoint");
}
this.endpoint = endpoint as SerialDeviceEndpoint;
Port = port ?? CreateSerialPort(this.endpoint);
observableReceiveSequence = Port.ToObservableCharacterSequence()
.Trace("Serial Receive")
.Publish();
}
private ISerialPort CreateSerialPort(SerialDeviceEndpoint endpoint)
{
Contract.Requires(endpoint != null);
var port = new SerialPort
{
PortName = endpoint.PortName,
BaudRate = endpoint.BaudRate,
Parity = endpoint.Parity,
DataBits = endpoint.DataBits,
StopBits = endpoint.StopBits,
RtsEnable = endpoint.RtsEnable,
DtrEnable = endpoint.DtrEnable,
Encoding = endpoint.Encoding,
Handshake = endpoint.Handshake
};
return(port);
}
