Extend and generalize data binding logic (#14)

Support for custom data binding attributes

MTSC/Common/Http/Attributes/FromBodyAttribute.cs

@@ -1,8 +1,12 @@
-using System;
+using MTSC.Common.Http.RoutingModules;
 
 namespace MTSC.Common.Http.Attributes
 {
-    public sealed class FromBodyAttribute : Attribute
+    public sealed class FromBodyAttribute : StringRouteDataBindingBaseAttribute
     {
+        public override string GetStringValue(HttpRouteBase route, RouteContext routeContext)
+        {
+            return routeContext.HttpRequest.BodyString;
+        }
     }
 }

MTSC/Common/Http/Attributes/FromHeadersAttribute.cs

@@ -1,8 +1,8 @@
-using System;
+using MTSC.Common.Http.RoutingModules;
 
 namespace MTSC.Common.Http.Attributes
 {
-    public sealed class FromHeadersAttribute : Attribute
+    public sealed class FromHeadersAttribute : StringRouteDataBindingBaseAttribute
     {
         public string HeaderName { get; }
 
@@ -10,5 +10,15 @@ namespace MTSC.Common.Http.Attributes
         {
             this.HeaderName = headerName;
         }
+
+        public override string GetStringValue(HttpRouteBase route, RouteContext routeContext)
+        {
+            if (routeContext.HttpRequest.Headers.ContainsHeader(this.HeaderName))
+            {
+                return routeContext.HttpRequest.Headers[this.HeaderName];
+            }
+
+            return null;
+        }
     }
 }

MTSC/Common/Http/Attributes/FromRouteContextResourcesAttribute.cs

@@ -1,8 +1,9 @@
-using System;
+using MTSC.Common.Http.RoutingModules;
+using System;
 
 namespace MTSC.Common.Http.Attributes
 {
-    public sealed class FromRouteContextResourcesAttribute : Attribute
+    public sealed class FromRouteContextResourcesAttribute : RouteDataBindingBaseAttribute
     {
         public string ResourceKey { get; }
 
@@ -10,5 +11,15 @@ namespace MTSC.Common.Http.Attributes
         {
             this.ResourceKey = resourceKey;
         }
+
+        public override object DataBind(HttpRouteBase route, RouteContext routeContext, Type propertyType)
+        {
+            if (routeContext.Resources.TryGetValue(this.ResourceKey, out var resource))
+            {
+                return resource;
+            }
+
+            return null;
+        }
     }
 }

MTSC/Common/Http/Attributes/FromUrlAttribute.cs

@@ -1,8 +1,8 @@
-using System;
+using MTSC.Common.Http.RoutingModules;
 
 namespace MTSC.Common.Http.Attributes
 {
-    public class FromUrlAttribute : Attribute
+    public class FromUrlAttribute : StringRouteDataBindingBaseAttribute
     {
         public string Placeholder { get; }
 
@@ -10,5 +10,15 @@ namespace MTSC.Common.Http.Attributes
         {
             this.Placeholder = placeholder;
         }
+
+        public override string GetStringValue(HttpRouteBase route, RouteContext routeContext)
+        {
+            if (routeContext.UrlValues.TryGetValue(this.Placeholder, out var value))
+            {
+                return value;
+            }
+
+            return null;
+        }
     }
 }

MTSC/Common/Http/Attributes/RouteDataBindingBaseAttribute.cs

@@ -0,0 +1,19 @@
+using MTSC.Common.Http.RoutingModules;
+using System;
+
+namespace MTSC.Common.Http.Attributes
+{
+    public abstract class RouteDataBindingBaseAttribute : Attribute
+    {
+        /// <summary>
+        /// Perform the data binding logic and return the bindable value.
+        /// This value will be attached to the decorated property.
+        /// The value can be 
+        /// </summary>
+        /// <param name="module"><see cref="HttpRouteBase"/> object.</param>
+        /// <param name="routeContext"><see cref="RouteContext"/> for the current request.</param>
+        /// <param name="propertyType"><see cref="Type"/> of property to be binded.</param>
+        /// <returns>Object to be binded to the decorated property.</returns>
+        public abstract object DataBind(HttpRouteBase route, RouteContext routeContext, Type propertyType);
+    }
+}

MTSC/Common/Http/Attributes/StringRouteDataBindingBaseAttribute.cs

@@ -0,0 +1,63 @@
+using MTSC.Common.Http.RoutingModules;
+using Newtonsoft.Json;
+using System;
+using System.ComponentModel;
+
+namespace MTSC.Common.Http.Attributes
+{
+    public abstract class StringRouteDataBindingBaseAttribute : RouteDataBindingBaseAttribute
+    {
+        public override sealed object DataBind(HttpRouteBase route, RouteContext routeContext, Type propertyType)
+        {
+            var stringValue = this.GetStringValue(route, routeContext);
+            return BindValue(propertyType, stringValue);
+        }
+
+        /// <summary>
+        /// Returns a string value that will later be converted to the decorated property <see cref="Type"/>.
+        /// Conversion tries <see cref="TypeConverter"/> as well as <see cref="JsonConvert"/> if the property <see cref="Type"/> is not <see cref="string"/>.
+        /// </summary>
+        /// <param name="module"><see cref="HttpRouteBase"/> route.</param>
+        /// <param name="routeContext"><see cref="RouteContext"/> of the request.</param>
+        /// <returns>A string value to be converted to the decorated property <see cref="Type"/>.</returns>
+        public abstract string GetStringValue(HttpRouteBase route, RouteContext routeContext);
+
+        private object BindValue(Type propertyType, string value)
+        {
+            object finalValue = null;
+            if (propertyType == typeof(string))
+            {
+                finalValue = value;
+            }
+            else if (this.TryConvertWithTypeConverter(propertyType, value, out var typeConvertedValue))
+            {
+                finalValue = typeConvertedValue;
+            }
+            else if (this.TryConvertWithJsonConvert(propertyType, value, out var jsonConvertedValue))
+            {
+                finalValue = jsonConvertedValue;
+            }
+
+            return finalValue;
+        }
+
+        private bool TryConvertWithTypeConverter(Type propertyType, string value, out object convertedValue)
+        {
+            var typeConverter = TypeDescriptor.GetConverter(propertyType);
+            if (typeConverter.CanConvertFrom(typeof(string)))
+            {
+                convertedValue = typeConverter.ConvertFrom(value);
+                return true;
+            }
+
+            convertedValue = null;
+            return false;
+        }
+
+        private bool TryConvertWithJsonConvert(Type propertyType, string value, out object convertedValue)
+        {
+            convertedValue = JsonConvert.DeserializeObject(value, propertyType);
+            return true;
+        }
+    }
+}

MTSC/Common/Http/RouteContext.cs

@@ -9,18 +9,22 @@ namespace MTSC.Common.Http
         public Server Server { get; }
         public HttpRequest HttpRequest { get; }
         public ClientData Client { get; }
+        public Dictionary<string, string> UrlValues { get; }
         public HttpResponse HttpResponse { get; set; }
         public CancellationToken CancelRequest => this.Client.CancellationToken;
         public Dictionary<string, object> Resources { get; set; } = new();
+        
 
         public RouteContext(
             Server server,
             HttpRequest httpRequest,
-            ClientData clientData)
+            ClientData clientData,
+            Dictionary<string, string> urlValues)
         {
             this.Server = server;
             this.HttpRequest = httpRequest;
             this.Client = clientData;
+            this.UrlValues = urlValues;
         }
     }
 }

MTSC/Exceptions/DataBindingException.cs

@@ -1,24 +1,31 @@
-using System;
+using MTSC.Common.Http;
+using MTSC.Common.Http.Attributes;
+using MTSC.Common.Http.RoutingModules;
+using System;
+using System.Reflection;
 using System.Runtime.Serialization;
 
 namespace MTSC.Exceptions
 {
-    public abstract class DataBindingException : Exception
+    public sealed class DataBindingException : Exception
     {
-        protected DataBindingException()
-        {
-        }
+        public HttpRouteBase Route { get; }
+        public RouteContext RouteContext { get; }
+        public RouteDataBindingBaseAttribute RouteDataBindingBaseAttribute { get; }
+        public PropertyInfo PropertyInfo { get; }
 
-        protected DataBindingException(string message) : base(message)
-        {
-        }
-
-        protected DataBindingException(string message, Exception innerException) : base(message, innerException)
-        {
-        }
-
-        protected DataBindingException(SerializationInfo info, StreamingContext context) : base(info, context)
+        public DataBindingException(
+            Exception innerException,
+            HttpRouteBase route,
+            RouteContext routeContext,
+            RouteDataBindingBaseAttribute routeDataBindingBaseAttribute,
+            PropertyInfo propertyInfo)
+            : base("Exception occurred during data binding. Check inner exception for details", innerException)
         {
+            this.Route = route;
+            this.RouteContext = routeContext;
+            this.RouteDataBindingBaseAttribute = routeDataBindingBaseAttribute;
+            this.PropertyInfo = propertyInfo;
         }
     }
 }

MTSC/Exceptions/FromBodyDataBindingException.cs

@@ -1,20 +0,0 @@
-using System;
-
-namespace MTSC.Exceptions
-{
-    public sealed class FromBodyDataBindingException : Exception
-    {
-        public Type PropertyType { get; }
-        public string Value { get; }
-
-        public FromBodyDataBindingException(
-            Exception innerException,
-            Type propertyType,
-            string value)
-            : base("Encountered exception when binding data from body", innerException)
-        {
-            this.PropertyType = propertyType;
-            this.Value = value;
-        }
-    }
-}

MTSC/Exceptions/FromHeadersDataBindingException.cs

@@ -1,23 +0,0 @@
-using System;
-
-namespace MTSC.Exceptions
-{
-    public sealed class FromHeadersDataBindingException : Exception
-    {
-        public Type PropertyType { get; }
-        public string Header { get; }
-        public string Value { get; }
-
-        public FromHeadersDataBindingException(
-            Exception innerException,
-            Type propertyType,
-            string header,
-            string value)
-            : base("Encountered exception when binding data from headers", innerException)
-        {
-            this.PropertyType = propertyType;
-            this.Header = header;
-            this.Value = value;
-        }
-    }
-}

MTSC/Exceptions/FromRouteContextResourcesDataBindingException.cs

@@ -1,24 +0,0 @@
-using System;
-using MTSC.Common.Http;
-
-namespace MTSC.Exceptions
-{
-    public sealed class FromRouteContextResourcesDataBindingException : Exception
-    {
-        public Type PropertyType { get; }
-        public string Key { get; }
-        public RouteContext RouteContext { get; }
-
-        public FromRouteContextResourcesDataBindingException(
-            Exception innerException,
-            Type propertyType,
-            string key,
-            RouteContext routeContext)
-            : base("Encountered exception when binding data from route context resources", innerException)
-        {
-            this.PropertyType = propertyType;
-            this.Key = key;
-            this.RouteContext = routeContext;
-        }
-    }
-}

MTSC/Exceptions/FromUrlDataBindingException.cs

@@ -1,23 +0,0 @@
-using System;
-
-namespace MTSC.Exceptions
-{
-    public sealed class FromUrlDataBindingException : DataBindingException
-    {
-        public Type PropertyType { get; }
-        public string Placeholder { get; }
-        public string Value { get; }
-
-        public FromUrlDataBindingException(
-            Exception innerException,
-            Type propertyType,
-            string placeHolder,
-            string value)
-            : base("Encountered exception when binding data from url", innerException)
-        {
-            this.PropertyType = propertyType;
-            this.Placeholder = placeHolder;
-            this.Value = value;
-        }
-    }
-}

MTSC/MTSC.csproj

@@ -5,13 +5,13 @@
     <TargetFrameworks>net48;netstandard2.0;netcoreapp3.1;net5.0;net6.0</TargetFrameworks>
     <ApplicationIcon />
     <StartupObject />
-    <Version>5.1.6</Version>
+    <Version>5.2.0</Version>
     <LangVersion>latest</LangVersion>
     <Authors>Alexandru-Victor Macocian</Authors>
     <Product>MTSC</Product>
     <Description>Modular TCP Server and Client</Description>
-    <AssemblyVersion>5.1.6.0</AssemblyVersion>
-    <FileVersion>5.1.6.0</FileVersion>
+    <AssemblyVersion>5.2.0.0</AssemblyVersion>
+    <FileVersion>5.2.0.0</FileVersion>
     <GeneratePackageOnBuild>true</GeneratePackageOnBuild>
     <Platforms>AnyCPU;x64</Platforms>
     <PackageProjectUrl>https://github.com/AlexMacocian/MTSC</PackageProjectUrl>

MTSC/ServerSide/Handlers/HttpRoutingHandler.cs

@@ -229,7 +229,11 @@ namespace MTSC.ServerSide.Handlers
                 httpLogger.LogRequest(server, this, client, request);
             }
 
-            var routeContext = new RouteContext(server, request, client);
+            var routeContext = new RouteContext(
+                server,
+                request,
+                client,
+                urlValues.ToDictionary(u => u.Placeholder, u => u.Value));
             foreach(var filterType in filterTypes)
             {
                 var filter = server.ServiceManager.GetService(filterType) as RouteFilterAttribute;
@@ -254,7 +258,7 @@ namespace MTSC.ServerSide.Handlers
             }
 
             
-            this.RouteHandleRequest(module, routeContext, filterTypes, urlValues).ContinueWith(task =>
+            this.RouteHandleRequest(module, routeContext, filterTypes).ContinueWith(task =>
             {
                 this.QueueResponse(client, task.Result);
             });
@@ -368,12 +372,11 @@ namespace MTSC.ServerSide.Handlers
         private async Task<HttpResponse> RouteHandleRequest(
             HttpRouteBase httpRouteBase,
             RouteContext routeContext,
-            List<Type> filterTypes,
-            List<UrlValue> urlValues)
+            List<Type> filterTypes)
         {
             try
             {
-                this.SetModuleProperties(httpRouteBase, routeContext, urlValues);
+                this.SetModuleProperties(httpRouteBase, routeContext);
                 var response = await httpRouteBase.CallHandleRequest(routeContext.HttpRequest);
                 routeContext.HttpResponse = response;
                 foreach (var filterType in filterTypes)
@@ -440,7 +443,7 @@ namespace MTSC.ServerSide.Handlers
             {
                 foreach (var attribute in property.GetCustomAttributes(true))
                 {
-                    if (attribute is FromUrlAttribute or FromBodyAttribute or FromHeadersAttribute)
+                    if (attribute is RouteDataBindingBaseAttribute)
                     {
                         propertyAndAttributesList.Add(((Attribute)attribute, property));
                     }
@@ -470,99 +473,29 @@ namespace MTSC.ServerSide.Handlers
             return false;
         }
 
-        private void SetModuleProperties(HttpRouteBase module, RouteContext routeContext, List<UrlValue> urlValues)
+        private void SetModuleProperties(HttpRouteBase module, RouteContext routeContext)
         {
-            var propertiesAndAttributes = this.routePropertyCache[module.GetType()];
             foreach ((var attribute, var propertyInfo) in this.routePropertyCache[module.GetType()])
             {
-                if (attribute is FromUrlAttribute fromUrlAttribute)
-                {
-                    var maybeValue = urlValues.Where(val => val.Placeholder == fromUrlAttribute.Placeholder).FirstOrDefault();
-                    if (maybeValue is not null)
-                    {
-                        try
-                        {
-                            this.TryAssignValue(propertyInfo, maybeValue.Value, module);
-                        }
-                        catch (Exception ex)
-                        {
-                            if (this.ThrowOnBindingErrors)
-                            {
-                                throw new FromUrlDataBindingException(ex, propertyInfo.PropertyType, maybeValue.Placeholder, maybeValue.Value);
-                            }
-                        }
-                    }
-                }
-                else if (attribute is FromBodyAttribute)
+                if (attribute is RouteDataBindingBaseAttribute routeDataBindingBaseAttribute)
                 {
                     try
                     {
-                        this.TryAssignValue(propertyInfo, routeContext.HttpRequest.BodyString, module);
+                        var value = routeDataBindingBaseAttribute.DataBind(module, routeContext, propertyInfo.PropertyType);
+                        SetPropertyValue(propertyInfo, value, module);
                     }
                     catch (Exception ex)
                     {
                         if (this.ThrowOnBindingErrors)
                         {
-                            throw new FromBodyDataBindingException(ex, propertyInfo.PropertyType, routeContext.HttpRequest.BodyString);
-                        }
-                    }
-                }
-                else if (attribute is FromHeadersAttribute fromHeadersAttribute)
-                {
-                    var maybeValue = routeContext.HttpRequest.Headers.Where(kvp => kvp.Key == fromHeadersAttribute.HeaderName).FirstOrDefault();
-                    if (maybeValue.Value is not null)
-                    {
-                        try
-                        {
-                            this.TryAssignValue(propertyInfo, maybeValue.Value, module);
-                        }
-                        catch (Exception ex)
-                        {
-                            if (this.ThrowOnBindingErrors)
-                            {
-                                throw new FromHeadersDataBindingException(ex, propertyInfo.PropertyType, fromHeadersAttribute.HeaderName, maybeValue.Value);
-                            }
-                        }
-                    }
-                }
-                else if (attribute is FromRouteContextResourcesAttribute fromRouteContextResourcesAttribute)
-                {
-                    if (routeContext.Resources.TryGetValue(fromRouteContextResourcesAttribute.ResourceKey, out var value))
-                    {
-                        try
-                        {
-                            SetPropertyValue(propertyInfo, value, module);
-                        }
-                        catch (Exception ex)
-                        {
-                            if (this.ThrowOnBindingErrors)
-                            {
-                                throw new FromRouteContextResourcesDataBindingException(ex, propertyInfo.PropertyType, fromRouteContextResourcesAttribute.ResourceKey, routeContext);
-                            }
+                            throw new DataBindingException(ex, module, routeContext, routeDataBindingBaseAttribute, propertyInfo);
                         }
                     }
                 }
             }
         }
 
-        private void TryAssignValue(PropertyInfo propertyInfo, string value, HttpRouteBase module)
-        {
-            object finalValue = null;
-            if (propertyInfo.PropertyType == typeof(string))
-            {
-                finalValue = value;
-            }
-            else if (this.TryConvertWithTypeConverter(propertyInfo, value, out var typeConvertedValue))
-            {
-                finalValue = typeConvertedValue;
-            }
-            else if (this.TryConvertWithJsonConvert(propertyInfo, value, out var jsonConvertedValue))
-            {
-                finalValue = jsonConvertedValue;
-            }
-
-            SetPropertyValue(propertyInfo, finalValue, module);
-        }
+        
 
         private static void SetPropertyValue(PropertyInfo propertyInfo, object value, HttpRouteBase module)
         {
@@ -577,47 +510,7 @@ namespace MTSC.ServerSide.Handlers
             }
         }
 
-        private bool TryConvertWithTypeConverter(PropertyInfo propertyInfo, string value, out object convertedValue)
-        {
-            try
-            {
-                var typeConverter = TypeDescriptor.GetConverter(propertyInfo.PropertyType);
-                if (typeConverter.CanConvertFrom(typeof(string)))
-                {
-                    convertedValue = typeConverter.ConvertFrom(value);
-                    return true;
-                }
-            }
-            catch
-            {
-                if (this.ThrowOnBindingErrors is true)
-                {
-                    throw;
-                }
-            }
-
-            convertedValue = null;
-            return false;
-        }
         
-        private bool TryConvertWithJsonConvert(PropertyInfo propertyInfo, string value, out object convertedValue)
-        {
-            try
-            {
-                convertedValue = JsonConvert.DeserializeObject(value, propertyInfo.PropertyType);
-                return true;
-            }
-            catch
-            {
-                if (this.ThrowOnBindingErrors is true)
-                {
-                    throw;
-                }
-            }
-
-            convertedValue = null;
-            return false;
-        }
 
         private static HttpResponse NotFound404 => new()
         {