Add support for accessing file body metadata from content headers: MimeType and FileName

Author: C0nquistadore

shared/Http/HttpParameterName.cs

@@ -0,0 +1,9 @@
+namespace Dibix.Http
+{
+    internal static class SpecialHttpParameterName
+    {
+        public const string Body = "body";
+        public const string MediaType = "mediaType";
+        public const string FileName = "fileName";
+    }
+}

shared/Http/SpecialHttpParameterName.cs

@@ -4,5 +4,7 @@
     internal sealed class BodyParameterSource : ActionParameterSourceDefinition<BodyParameterSource>
     {
         public const string RawPropertyName = "$RAW";
+        public const string MediaTypePropertyName = "$MEDIATYPE";
+        public const string FileNamePropertyName = "$FILENAME";
     }
 }

shared/ParameterSources/BodyParameterSource.cs

@@ -4,7 +4,6 @@
 using System.Linq;
 using System.Net;
 using System.Security.Claims;
-using System.Threading.Tasks;
 using Dibix.Http.Server;
 using Dibix.Http.Server.AspNetCore;
 using Microsoft.AspNetCore.Authentication;
@@ -23,7 +22,11 @@ public HttpRequestDescriptor(HttpRequest request)
 
         public string GetPath() => $"{_request.PathBase}{_request.Path}";
 
-        public Task<Stream> GetBody() => Task.FromResult(_request.Body);
+        public Stream GetBody() => _request.Body;
+
+        public string? GetBodyMediaType() => _request.GetTypedHeaders().ContentType?.MediaType.Value;
+
+        public string? GetBodyFileName() => _request.GetTypedHeaders().ContentDisposition?.FileName.Value;
 
         public IEnumerable<string> GetHeaderValues(string name) => _request.Headers[name];
 

src/Dibix.Http.Host/Model/HttpRequestDescriptor.cs

@@ -21,7 +21,11 @@ public HttpRequestMessageDescriptor(HttpRequestMessage request)
 
         public string GetPath() => RequestMessage.RequestUri!.AbsolutePath;
 
-        public async Task<Stream> GetBody() => RequestMessage.Content != null ? await RequestMessage.Content.ReadAsStreamAsync().ConfigureAwait(false) : null;
+        public Stream GetBody() => RequestMessage.Content?.ReadAsStreamAsync().GetAwaiter().GetResult();
+
+        public string GetBodyMediaType() => RequestMessage.Content?.Headers.ContentType?.MediaType;
+
+        public string GetBodyFileName() => RequestMessage.Content?.Headers.ContentDisposition?.FileName;
 
         public IEnumerable<string> GetHeaderValues(string name) => RequestMessage.Headers.TryGetValues(name, out IEnumerable<string> values) ? values : Enumerable.Empty<string>();
 

src/Dibix.Http.Server.AspNet/HttpRequestMessageDescriptor.cs

@@ -12,9 +12,9 @@
     <Compile Include="..\..\shared\Http\HttpApiMethod.cs" Link="Model\%(Filename)%(Extension)" />
     <Compile Include="..\..\shared\Http\HttpErrorResponseUtility.cs" Link="Runtime\%(Filename)%(Extension)" />
     <Compile Include="..\..\shared\Http\HttpParameterUtility.cs" Link="Runtime\%(Filename)%(Extension)" />
-    <Compile Include="..\..\shared\Http\HttpParameterName.cs" Link="Runtime\%(Filename)%(Extension)" />
     <Compile Include="..\..\shared\Http\ModelContextProtocolType.cs" Link="Runtime\%(Filename)%(Extension)" />
     <Compile Include="..\..\shared\Http\RouteBuilder.cs" Link="Utilities\%(Filename)%(Extension)" />
+    <Compile Include="..\..\shared\Http\SpecialHttpParameterName.cs" Link="Runtime\%(Filename)%(Extension)" />
     <Compile Include="..\..\shared\Metadata\IPropertyDescriptor.cs" Link="Model\%(Filename)%(Extension)" />
     <Compile Include="..\..\shared\Metadata\NestedEnumerablePair.cs" Link="Model\%(Filename)%(Extension)" />
     <Compile Include="..\..\shared\Metadata\PrimitiveType.cs" Link="Model\%(Filename)%(Extension)" />

src/Dibix.Http.Server/Dibix.Http.Server.csproj

@@ -2,14 +2,15 @@
 using System.Collections.Generic;
 using System.IO;
 using System.Security.Claims;
-using System.Threading.Tasks;
 
 namespace Dibix.Http.Server
 {
     public interface IHttpRequestDescriptor
     {
         string GetPath();
-        Task<Stream> GetBody();
+        Stream GetBody();
+        string GetBodyMediaType();
+        string GetBodyFileName();
         IEnumerable<string> GetHeaderValues(string name);
         IEnumerable<string> GetAcceptLanguageValues();
         ClaimsPrincipal GetUser();

src/Dibix.Http.Server/Model/IHttpRequestDescriptor.cs

@@ -1,8 +1,5 @@
 using System;
-using System.IO;
 using System.Linq.Expressions;
-using System.Runtime.CompilerServices;
-using System.Threading.Tasks;
 
 namespace Dibix.Http.Server
 {
@@ -12,19 +9,36 @@ internal sealed class BodyParameterSourceProvider : NonUserParameterSourceProvid
 
         public override void Resolve(IHttpParameterResolutionContext context)
         {
-            if (context.PropertyPath != BodyParameterSource.RawPropertyName)
+            switch (context.PropertyPath)
             {
-                Type instanceType = context.ActionMetadata.SafeGetBodyContract();
-                Expression instanceValue = Expression.Call(typeof(HttpParameterResolverUtility), nameof(HttpParameterResolverUtility.ReadBody), new[] { instanceType }, context.ArgumentsParameter);
-                context.ResolveUsingInstanceProperty(instanceType, instanceValue, ensureNullPropagation: true);
-            }
-            else
-            {
-                // TODO: Can be null!
-                Expression getBodyCall = Expression.Call(context.RequestParameter, nameof(IHttpRequestDescriptor.GetBody), Type.EmptyTypes);
-                Expression getAwaiterCall = Expression.Call(getBodyCall, typeof(Task<Stream>).SafeGetMethod(nameof(Task<Stream>.GetAwaiter)));
-                Expression getResultCall = Expression.Call(getAwaiterCall, nameof(TaskAwaiter.GetResult), Type.EmptyTypes);
-                context.ResolveUsingValue(getResultCall);
+                case BodyParameterSource.RawPropertyName:
+                {
+                    Expression getBodyCall = Expression.Call(context.RequestParameter, nameof(IHttpRequestDescriptor.GetBody), Type.EmptyTypes);
+                    context.ResolveUsingValue(getBodyCall);
+                    break;
+                }
+
+                case BodyParameterSource.MediaTypePropertyName:
+                {
+                    Expression getBodyMediaTypeCall = Expression.Call(context.RequestParameter, nameof(IHttpRequestDescriptor.GetBodyMediaType), Type.EmptyTypes);
+                    context.ResolveUsingValue(getBodyMediaTypeCall);
+                    break;
+                }
+
+                case BodyParameterSource.FileNamePropertyName:
+                {
+                    Expression getBodyFileNameCall = Expression.Call(context.RequestParameter, nameof(IHttpRequestDescriptor.GetBodyFileName), Type.EmptyTypes);
+                    context.ResolveUsingValue(getBodyFileNameCall);
+                    break;
+                }
+
+                default:
+                {
+                    Type instanceType = context.ActionMetadata.SafeGetBodyContract();
+                    Expression instanceValue = Expression.Call(typeof(HttpParameterResolverUtility), nameof(HttpParameterResolverUtility.ReadBody), [instanceType], context.ArgumentsParameter);
+                    context.ResolveUsingInstanceProperty(instanceType, instanceValue, ensureNullPropagation: true);
+                    break;
+                }
             }
         }
     }

src/Dibix.Http.Server/Providers/BodyParameterSourceProvider.cs

@@ -825,7 +825,7 @@ private static void CollectApiParameters(HttpParameterResolutionMethod method, I
                 // If the target method does not expect a parameter of the body type, we have to add a pseudo parameter
                 // That way ASP.NET will use a formatter binding and read the body for us, which we can later read from the arguments dictionary.
                 if (parameters.All(x => x.ParameterType != bodyContract))
-                    method.AddParameter(HttpParameterName.Body, bodyContract, HttpParameterLocation.NonUser, isOptional: false);
+                    method.AddParameter(SpecialHttpParameterName.Body, bodyContract, HttpParameterLocation.NonUser, isOptional: false);
             }
 
             foreach (HttpParameterInfo parameter in parameters.Where(x => x.Location != HttpParameterLocation.NonUser).DistinctBy(x => x.ApiParameterName))

src/Dibix.Http.Server/Runtime/HttpParameterResolver.cs

@@ -22,7 +22,7 @@ public static TResult ReadArgument<TResult>(IDictionary<string, object> argument
             return (TResult)value;
         }
 
-        public static TBody ReadBody<TBody>(IDictionary<string, object> arguments) => ReadArgument<TBody>(arguments, HttpParameterName.Body);
+        public static TBody ReadBody<TBody>(IDictionary<string, object> arguments) => ReadArgument<TBody>(arguments, SpecialHttpParameterName.Body);
 
         public static Expression BuildWritableArgumentAccessorExpression(Expression argumentsParameter, string key)
         {