Merge pull request #11005 from abpframework/AbpRemoteStreamContentModelBinder

Enhance `AbpRemoteStreamContentModelBinder` class.

framework/src/Volo.Abp.AspNetCore.Mvc/Volo/Abp/AspNetCore/Mvc/ContentFormatters/AbpRemoteStreamContentModelBinder.cs

@@ -8,7 +8,8 @@ using Volo.Abp.Content;
 
 namespace Volo.Abp.AspNetCore.Mvc.ContentFormatters
 {
-    public class AbpRemoteStreamContentModelBinder : IModelBinder
+    public class AbpRemoteStreamContentModelBinder<TRemoteStreamContent> : IModelBinder
+        where TRemoteStreamContent: class, IRemoteStreamContent
     {
         public async Task BindModelAsync(ModelBindingContext bindingContext)
         {
@@ -17,7 +18,7 @@ namespace Volo.Abp.AspNetCore.Mvc.ContentFormatters
                 throw new ArgumentNullException(nameof(bindingContext));
             }
 
-            var postedFiles = new List<IRemoteStreamContent>();
+            var postedFiles = GetCompatibleCollection<TRemoteStreamContent>(bindingContext);
 
             // If we're at the top level, then use the FieldName (parameter or property name).
             // This handles the fact that there will be nothing in the ValueProviders for this parameter
@@ -42,7 +43,7 @@ namespace Volo.Abp.AspNetCore.Mvc.ContentFormatters
             }
 
             object value;
-            if (bindingContext.ModelType == typeof(IRemoteStreamContent) || bindingContext.ModelType == typeof(RemoteStreamContent))
+            if (bindingContext.ModelType == typeof(TRemoteStreamContent))
             {
                 if (postedFiles.Count == 0)
                 {
@@ -63,7 +64,7 @@ namespace Volo.Abp.AspNetCore.Mvc.ContentFormatters
 
                 // Perform any final type mangling needed.
                 var modelType = bindingContext.ModelType;
-                if (modelType == typeof(IRemoteStreamContent[]) || modelType == typeof(RemoteStreamContent[]))
+                if (modelType == typeof(TRemoteStreamContent[]))
                 {
                     value = postedFiles.ToArray();
                 }
@@ -91,7 +92,7 @@ namespace Volo.Abp.AspNetCore.Mvc.ContentFormatters
         private async Task GetFormFilesAsync(
             string modelName,
             ModelBindingContext bindingContext,
-            ICollection<IRemoteStreamContent> postedFiles)
+            ICollection<TRemoteStreamContent> postedFiles)
         {
             var request = bindingContext.HttpContext.Request;
             if (request.HasFormContentType)
@@ -108,14 +109,53 @@ namespace Volo.Abp.AspNetCore.Mvc.ContentFormatters
 
                     if (file.Name.Equals(modelName, StringComparison.OrdinalIgnoreCase))
                     {
-                        postedFiles.Add(new RemoteStreamContent(file.OpenReadStream(), file.FileName, file.ContentType, file.Length));
+                        postedFiles.Add(new RemoteStreamContent(file.OpenReadStream(), file.FileName, file.ContentType, file.Length).As<TRemoteStreamContent>());
                     }
                 }
             }
             else if (bindingContext.IsTopLevelObject)
             {
-                postedFiles.Add(new RemoteStreamContent(request.Body, null, request.ContentType, request.ContentLength));
+                postedFiles.Add(new RemoteStreamContent(request.Body, null, request.ContentType, request.ContentLength).As<TRemoteStreamContent>());
             }
         }
+
+        private static ICollection<T> GetCompatibleCollection<T>(ModelBindingContext bindingContext)
+        {
+            var model = bindingContext.Model;
+            var modelType = bindingContext.ModelType;
+
+            // There's a limited set of collection types we can create here.
+            //
+            // For the simple cases: Choose List<T> if the destination type supports it (at least as an intermediary).
+            //
+            // For more complex cases: If the destination type is a class that implements ICollection<T>, then activate
+            // an instance and return that.
+            //
+            // Otherwise just give up.
+            if (typeof(T).IsAssignableFrom(modelType))
+            {
+                return new List<T>();
+            }
+
+            if (modelType == typeof(T[]))
+            {
+                return new List<T>();
+            }
+
+            // Does collection exist and can it be reused?
+            if (model is ICollection<T> collection && !collection.IsReadOnly)
+            {
+                collection.Clear();
+
+                return collection;
+            }
+
+            if (modelType.IsAssignableFrom(typeof(List<T>)))
+            {
+                return new List<T>();
+            }
+
+            return (ICollection<T>)Activator.CreateInstance(modelType);
+        }
     }
 }

framework/src/Volo.Abp.AspNetCore.Mvc/Volo/Abp/AspNetCore/Mvc/ContentFormatters/AbpRemoteStreamContentModelBinderProvider.cs

@@ -14,12 +14,16 @@ namespace Volo.Abp.AspNetCore.Mvc.ContentFormatters
                 throw new ArgumentNullException(nameof(context));
             }
 
-            if (context.Metadata.ModelType == typeof(IRemoteStreamContent) ||
-                context.Metadata.ModelType == typeof(RemoteStreamContent) ||
-                typeof(IEnumerable<IRemoteStreamContent>).IsAssignableFrom(context.Metadata.ModelType) ||
+            if (context.Metadata.ModelType == typeof(RemoteStreamContent) ||
                 typeof(IEnumerable<RemoteStreamContent>).IsAssignableFrom(context.Metadata.ModelType))
             {
-                return new AbpRemoteStreamContentModelBinder();
+                return new AbpRemoteStreamContentModelBinder<RemoteStreamContent>();
+            }
+
+            if (context.Metadata.ModelType == typeof(IRemoteStreamContent) ||
+                typeof(IEnumerable<IRemoteStreamContent>).IsAssignableFrom(context.Metadata.ModelType))
+            {
+                return new AbpRemoteStreamContentModelBinder<IRemoteStreamContent>();
             }
 
             return null;

framework/test/Volo.Abp.Http.Client.Tests/Volo/Abp/Http/DynamicProxying/PersonAppServiceClientProxy_Tests.cs

@@ -263,7 +263,7 @@ namespace Volo.Abp.Http.DynamicProxying
             var result = await _peopleAppService.CreateMultipleFileAsync(new CreateMultipleFileInput()
             {
                 Name = "123.rtf",
-                Contents = new List<IRemoteStreamContent>()
+                Contents = new List<RemoteStreamContent>()
                 {
                     new RemoteStreamContent(memoryStream, "1-1.rtf", "application/rtf"),
                     new RemoteStreamContent(memoryStream2, "1-2.rtf", "application/rtf2")

framework/test/Volo.Abp.TestApp/Volo/Abp/TestApp/Application/Dto/CreateFileInput.cs

@@ -6,6 +6,6 @@ namespace Volo.Abp.TestApp.Application.Dto
     {
         public string Name { get; set; }
 
-        public RemoteStreamContent Content { get; set; }
+        public IRemoteStreamContent Content { get; set; }
     }
 }

framework/test/Volo.Abp.TestApp/Volo/Abp/TestApp/Application/Dto/CreateMultipleFileInput.cs

@@ -7,7 +7,7 @@ namespace Volo.Abp.TestApp.Application.Dto
     {
         public string Name { get; set; }
 
-        public IEnumerable<IRemoteStreamContent> Contents { get; set; }
+        public IEnumerable<RemoteStreamContent> Contents { get; set; }
 
         public CreateFileInput Inner { get; set; }
     }