Make OptionFactory a object

src/CoAPNet/CoapMessage.cs

@@ -39,92 +39,9 @@ public enum CoapMessageType
     public enum CoapMessageCodeClass
     {
         Request = 0,
-        Success = 200,
-        ClientError = 400,
-        ServerError = 500
-    }
-
-    /// <summary>
-    /// Response Codes
-    /// <para>See section 5.9 of [RFC7252] and section 12.1 of [RFC7252]</para>
-    /// </summary>
-    public enum CoapMessageCode
-    {
-        /// <summary>
-        /// Placeholder and will throw <see cref="InvalidOperationException"/> when used.
-        /// </summary>
-        None = 0,
-        // 0.xx Request
-        /// <summary>
-        /// GET request from a client to a server used for retreiving resources
-        /// </summary>
-        Get = 1,
-        /// <summary>
-        /// Post request from a client to a server used for creating or updating resources
-        /// </summary>
-        Post = 2,
-        /// <summary>
-        /// Put request from a client to a server used for updating resources
-        /// </summary>
-        Put = 3,
-        /// <summary>
-        /// DELETE request from a client to a server used to delete resources
-        /// </summary>
-        Delete = 4,
-        // 2.xx Success
-        Created = 201,
-        Deleted = 202,
-        Valid = 203,
-        Changed = 204,
-        Content = 205,
-        // 4.xx Client Error
-        BadRequest = 400,
-        Unauthorized = 401,
-        BadOption = 402,
-        Forbidden = 403,
-        NotFound = 404,
-        MethodNotAllowed = 405,
-        NotAcceptable = 406,
-        PreconditionFailed = 412,
-        RequestEntityTooLarge = 413,
-        UnsupportedContentFormat = 415,
-        // 5.xx Server Error
-        InternalServerError = 500,
-        NotImplemented = 501,
-        BadGateway = 502,
-        ServiceUnavailable = 503,
-        GatewayTimeout = 504,
-        ProxyingNotSupported = 505
-    }
-
-    /// <summary>
-    /// Extension methods for quickly deciding which logic to apply to CoAP messages.
-    /// </summary>
-    public static class CoapMessageCodeExtensions
-    {
-        /// <summary>
-        /// indicates if the CoAP message is a Request from a client.
-        /// </summary>
-        public static bool IsRequest(this CoapMessageCode code)
-            => ((int) code / 100) == 0 && code != CoapMessageCode.None;
-
-        /// <summary>
-        /// indicates if the CoAP message is a successful response from a server.
-        /// </summary>
-        public static bool IsSuccess(this CoapMessageCode code)
-            => ((int)code / 100) == 2;
-
-        /// <summary>
-        /// indicates if the CoAP message is a error due to a client's request.
-        /// </summary>
-        public static bool IsClientError(this CoapMessageCode code)
-            => ((int)code / 100) == 4;
-
-        /// <summary>
-        /// indicates if the CoAP message is a error due to internal server issues.
-        /// </summary>
-        public static bool IsServerError(this CoapMessageCode code)
-            => ((int)code / 100) == 5;
+        Success = 2,
+        ClientError = 4,
+        ServerError = 5
     }
 
     /// <summary>
@@ -209,6 +126,7 @@ public byte[] Token
         public int Id { get; set; }
 
         private List<CoapOption> _options = new List<CoapOption>();
+
         /// <summary>
         /// Gets or sets the list of options to be encoded into the message header. The order of these options are Critical and spcial care is needed when adding new items.
         /// <para>Todo: Sort items based on <see cref="CoapOption.OptionNumber"/> and preserve options with identical Optionnumbers</para>
@@ -224,6 +142,17 @@ public List<CoapOption> Options
             }
         }
 
+        private OptionFactory _optionFactory;
+
+        /// <summary>
+        /// Gets or Sets the OptionFactory used when decoding options in a CoAP message header
+        /// </summary>
+        public OptionFactory OptionFactory
+        {
+            get => _optionFactory ?? (_optionFactory = OptionFactory.Default);
+            set => _optionFactory = value;
+        }
+
         /// <summary>
         /// Gets or Sets The paylaod of the message.
         /// </summary>
@@ -411,7 +340,7 @@ public void Deserialise(byte[] data)
 
                 try
                 {
-                    var option = CoAPNet.Options.Factory.Create(optCode + optionDelta,
+                    var option = OptionFactory.Create(optCode + optionDelta,
                         data.Skip(i + 1).Take(dataLen).ToArray());
                     if (option != null)
                         Options.Add(option);

src/CoAPNet/Options/OptionFactory.cs

@@ -0,0 +1,104 @@
+using System;
+using System.Reflection;
+using System.Collections.Generic;
+
+namespace CoAPNet.Options
+{
+    public class OptionFactory
+    {
+        private Dictionary<int, Type> _options = new Dictionary<int, Type>();
+
+        private static OptionFactory _instance;
+
+        /// <summary>
+        /// A <see cref="OptionFactory"/> with all the supported options registered.
+        /// </summary>
+        public static OptionFactory Default => _instance ?? (_instance = new OptionFactory());
+
+        /// <summary>
+        /// Creates a new Options Factory with all the suported options registered.
+        /// </summary>
+        public OptionFactory()
+        {
+            Register<UriHost>();
+            Register<UriPort>();
+            Register<UriPath>();
+            Register<UriQuery>();
+
+            Register<ProxyUri>();
+            Register<ProxyScheme>();
+
+            Register<LocationPath>();
+            Register<LocationQuery>();
+
+            Register<ContentFormat>();
+            Register<Accept>();
+            Register<MaxAge>();
+            Register<ETag>();
+            Register<Size1>();
+
+            Register<IfMatch>();
+            Register<IfNoneMatch>();
+        }
+
+        /// <summary>
+        /// Creates a new Options Factory with all the suported options registered and registers addional <see cref="CoapOption"/>.
+        /// </summary>
+        /// <param name="addtionalOptions"></param>
+        public OptionFactory(params Type[] addtionalOptions)
+            : this()
+        {
+            Register(addtionalOptions);
+        }
+
+        /// <summary>
+        /// Register an additional <see cref="CoapOption"/>
+        /// </summary>
+        /// <typeparam name="T">Must subclass <see cref="CoapOption"/></typeparam>
+        public void Register<T>() where T : CoapOption
+        {
+            Register(typeof(T));
+        }
+
+        /// <summary>
+        /// Regisrers additional <see cref="CoapOption"/>s
+        /// </summary>
+        /// <param name="addtionalOptions"></param>
+        public void Register(params Type[] addtionalOptions)
+        {
+            foreach (var type in addtionalOptions)
+            {
+                if (!type.GetTypeInfo().IsSubclassOf(typeof(CoapOption)))
+                    throw new ArgumentException($"Type must be a subclass of {nameof(CoapOption)}");
+
+                var option = (CoapOption)Activator.CreateInstance(type);
+                _options.Add(option.OptionNumber, type);
+            }
+        }
+
+        /// <summary>
+        /// Try to create an <see cref="CoapOption"/> from the option number and data. 
+        /// </summary>
+        /// <param name="number"></param>
+        /// <param name="data"></param>
+        /// <returns><value>null</value> if the option is unsupported.</returns>
+        /// <exception cref="CoapOptionException">If the option number is unsuppported and is critical (See RFC 7252 Section 5.4.1)</exception>
+        public CoapOption Create(int number, byte[] data = null)
+        {
+            // Let the exception get thrown if index is out of range
+            Type type = null;
+            if (!_options.TryGetValue(number, out type))
+            {
+                if (number % 2 == 1)
+                    throw new CoapOptionException($"Unsupported critical option ({number})", new ArgumentOutOfRangeException(nameof(number)));
+                return null;
+            }
+
+            var option = (CoapOption)Activator.CreateInstance(type);
+            if (data != null)
+                option.FromBytes(data);
+
+            return option;
+        }
+    }
+}