added support for streaming as per issue #5

example/back-end/ApiBackEnd/ApiBackEnd.csproj

@@ -120,6 +120,7 @@
     <Compile Include="Properties\AssemblyInfo.cs" />
     <Compile Include="Services\NotImplementedMultipartFormDataModelBinderService.cs" />
     <Compile Include="Startup.cs" />
+    <Compile Include="ViewModels\BasicUploadStreamedViewModel.cs" />
     <Compile Include="ViewModels\BasicUploadViewModel.cs" />
     <Compile Include="ViewModels\ClientResponseViewModel.cs" />
     <Compile Include="ViewModels\StudentViewModel.cs" />

example/back-end/ApiBackEnd/Controllers/ApiUploadController.cs

@@ -34,6 +34,30 @@ public IHttpActionResult BasicUpload(BasicUploadViewModel info)
             return Ok(new ClientResponseViewModel(messages));
         }
 
+        /// <summary>
+        /// Upload attachment to service end-point using streaming.
+        /// </summary>
+        /// <returns></returns>
+        [Route("basic-upload-streamed")]
+        [HttpPost]
+        public IHttpActionResult BasicUploadStreamed(BasicUploadStreamedViewModel info)
+        {
+            if (info == null)
+            {
+                info = new BasicUploadStreamedViewModel();
+                Validate(info);
+            }
+
+            if (!ModelState.IsValid)
+                return BadRequest(ModelState);
+
+            var messages = new List<string>();
+            messages.Add($"Author information: {info.Author.FullName}");
+            messages.Add($"Attachment information: (Mime) {info.StreamedAttachment.MediaType} - (File name) {info.StreamedAttachment.Name}");
+
+            return Ok(new ClientResponseViewModel(messages));
+        }
+
         /// <summary>
         /// Upload a list of attachment with author information.
         /// </summary>

example/back-end/ApiBackEnd/ViewModels/BasicUploadStreamedViewModel.cs

@@ -0,0 +1,28 @@
+using System;
+using System.ComponentModel.DataAnnotations;
+using ApiBackEnd.Models;
+using ApiMultiPartFormData.Models;
+
+namespace ApiBackEnd.ViewModels
+{
+    public class BasicUploadStreamedViewModel
+    {
+        #region Properties
+
+        public Guid Id { get; set; }
+
+        /// <summary>
+        /// Author information.
+        /// </summary>
+        [Required]
+        public User Author { get; set; }
+
+        /// <summary>
+        /// Attachment.
+        /// </summary>
+        [Required]
+        public StreamedHttpFile StreamedAttachment { get; set; }
+
+        #endregion
+    }
+}

lib/ApiMultipartFormDataFormatter/ApiMultiPartFormData.csproj

@@ -56,6 +56,8 @@
   </ItemGroup>
   <ItemGroup>
     <Compile Include="ApiMultipartFormDataFormatter.cs" />
+    <Compile Include="Models\HttpFileBase.cs" />
+    <Compile Include="Models\StreamedHttpFile.cs" />
     <Compile Include="Services\Implementations\BaseMultiPartFormDataModelBinderService.cs" />
     <Compile Include="Services\Interfaces\IMultiPartFormDataModelBinderService.cs" />
     <Compile Include="Models\HttpFile.cs" />

lib/ApiMultipartFormDataFormatter/Models/HttpFile.cs

@@ -1,19 +1,9 @@
 namespace ApiMultiPartFormData.Models
 {
-    public class HttpFile
+    public class HttpFile : HttpFileBase
     {
         #region Properties
 
-        /// <summary>
-        ///     Name of file.
-        /// </summary>
-        public string Name { get; set; }
-
-        /// <summary>
-        ///     Type of file.
-        /// </summary>
-        public string MediaType { get; set; }
-
         /// <summary>
         ///     Serialized byte stream of file.
         /// </summary>

lib/ApiMultipartFormDataFormatter/Models/HttpFileBase.cs

@@ -0,0 +1,19 @@
+namespace ApiMultiPartFormData.Models
+{
+    public abstract class HttpFileBase
+    {
+        #region Properties
+
+        /// <summary>
+        ///     Name of file.
+        /// </summary>
+        public string Name { get; set; }
+
+        /// <summary>
+        ///     Type of file.
+        /// </summary>
+        public string MediaType { get; set; }
+
+        #endregion
+    }
+}

lib/ApiMultipartFormDataFormatter/Models/StreamedHttpFile.cs

@@ -0,0 +1,52 @@
+using System;
+using System.IO;
+
+namespace ApiMultiPartFormData.Models
+{
+    public class StreamedHttpFile : HttpFileBase
+    {
+        #region Properties
+
+        /// <summary>
+        ///     Stream containing file contents.
+        /// </summary>
+        public Stream Stream { get; set; }
+
+        /// <summary>
+        ///     Length of file stream
+        /// </summary>
+        public long StreamLength
+        {
+            get
+            {
+                return Stream.Length;
+            }
+        }
+
+        #endregion
+
+        #region Constructors
+
+        /// <summary>
+        ///     Initialize an instance of StreamedHttpFile without any setting.
+        /// </summary>
+        public StreamedHttpFile()
+        {
+        }
+
+        /// <summary>
+        ///     Initialize an instance of StreamedHttpFile with parameters.
+        /// </summary>
+        /// <param name="fileName"></param>
+        /// <param name="mediaType"></param>
+        /// <param name="stream"></param>
+        public StreamedHttpFile(string fileName, string mediaType, Stream stream)
+        {
+            Name = fileName;
+            MediaType = mediaType;
+            Stream = stream;
+        }
+
+        #endregion
+    }
+}

lib/ApiMultipartFormDataFormatter/MultipartFormDataFormatter.cs

@@ -125,17 +125,27 @@ public override async Task<object> ReadFromStreamAsync(Type type, Stream stream,
 
                         // Content is a file.
                         // File retrieved from client-side.
-                        HttpFile file;
+
+                        HttpFileBase file = null;
 
                         // set null if no content was submitted to have support for [Required]
                         if (httpContent.Headers.ContentLength.GetValueOrDefault() > 0)
-                            file = new HttpFile(
-                                httpContent.Headers.ContentDisposition.FileName.Trim('"'),
-                                httpContent.Headers.ContentType.MediaType,
-                                await httpContent.ReadAsByteArrayAsync()
-                            );
-                        else
-                            file = null;
+                        {
+                            if (IsStreamingRequested(instance, contentParameter))
+                            {
+                                file = new StreamedHttpFile(
+                                    httpContent.Headers.ContentDisposition.FileName.Trim('"'),
+                                    httpContent.Headers.ContentType.MediaType,
+                                    await httpContent.ReadAsStreamAsync());
+                            }
+                            else
+                            {
+                                file = new HttpFile(
+                                    httpContent.Headers.ContentDisposition.FileName.Trim('"'),
+                                    httpContent.Headers.ContentType.MediaType,
+                                    await httpContent.ReadAsByteArrayAsync());
+                            }
+                        }
 
                         await BuildRequestModelAsync(instance, parameterParts, file, dependencyScope);
                     }
@@ -380,6 +390,11 @@ private PropertyInfo FindPropertyInfoFromPointer(object instance, string name)
                     .FirstOrDefault(x => name.Equals(x.Name, StringComparison.InvariantCultureIgnoreCase));
         }
 
+        private bool IsStreamingRequested(object instance, string contentParameter)
+        {
+            return instance.GetType().GetProperty(contentParameter)?.PropertyType == typeof(StreamedHttpFile);
+        }
+
         /// <summary>
         ///     Check whether text is only numeric or not.
         /// </summary>