1340 Improve support for Binary endpoint

src/Hl7.Fhir.Base/Rest/BaseFhirClient.cs

@@ -1079,7 +1079,7 @@ private static ResourceIdentity verifyResourceIdentity(Uri location, bool needId
             // of the server, add a suggestion about this in the (legacy) parsing exception.
             var suggestedVersionOnParseError = !Settings.VerifyFhirVersion ? fhirVersion : null;
             (LastResult, LastBody, LastBodyAsText, LastBodyAsResource, var issue) =
-                await ValidateResponse(responseMessage, expect, _serializationEngine, suggestedVersionOnParseError)
+                await ValidateResponse(responseMessage, expect, _serializationEngine, suggestedVersionOnParseError, useBinaryProtocol: false)
                 .ConfigureAwait(false);
 
             // If an error occurred while trying to interpret and validate the response, we will bail out now.
@@ -1135,10 +1135,15 @@ static string unexpectedBodyType(Bundle.RequestComponent rc) => $"Operation {rc.
         /// <exception cref="FhirOperationException">The body content type could not be handled or the response status indicated failure, or we received an unexpected success status.</exception>
         /// <exception cref="FormatException">Thrown when the original ITypedElement-based parsers are used and a parse exception occurred.</exception>
         /// <exception cref="DeserializationFailedException">Thrown when a newer parsers is used and a parse exception occurred.</exception>
-        /// <seealso cref="HttpContentParsers.ExtractResponseData(HttpResponseMessage, IFhirSerializationEngine)"/>
-        internal static async Task<ResponseData> ValidateResponse(HttpResponseMessage responseMessage, IEnumerable<HttpStatusCode> expect, IFhirSerializationEngine engine, string? suggestedVersionOnParseError)
-        {
-            var responseData = (await responseMessage.ExtractResponseData(engine).ConfigureAwait(false))
+        /// <seealso cref="HttpContentParsers.ExtractResponseData(HttpResponseMessage, IFhirSerializationEngine, bool)"/>
+        internal static async Task<ResponseData> ValidateResponse(
+            HttpResponseMessage responseMessage,
+            IEnumerable<HttpStatusCode> expect,
+            IFhirSerializationEngine engine,
+            string? suggestedVersionOnParseError,
+            bool useBinaryProtocol)
+        {
+            var responseData = (await responseMessage.ExtractResponseData(engine, useBinaryProtocol).ConfigureAwait(false))
                 .TranslateUnsupportedBodyTypeException(responseMessage.StatusCode)
                 .TranslateLegacyParserException(suggestedVersionOnParseError);
 

src/Hl7.Fhir.Base/Rest/EntryToHttpExtensions.cs

@@ -19,7 +19,7 @@ namespace Hl7.Fhir.Rest
 
 
     internal static class EntryToHttpExtensions
-    {     
+    {
         public static HttpRequestMessage ToHttpRequestMessage(
             this Bundle.EntryComponent entry,
             Uri baseUrl,
@@ -63,7 +63,7 @@ HttpRequestMessage setBody(HttpRequestMessage message)
 
                 message = entry.Resource switch
                 {
-                    Binary bin => message.WithBinaryContent(bin),
+                    Binary binaryData when settings.BinaryTransfer is BinaryTransferBehaviour.UseData => message.WithBinaryContent(binaryData),
                     Parameters pars when isSearchUsingPost => message.WithFormUrlEncodedParameters(pars),
                     Resource resource => message.WithResourceContent(resource, serialization, ser, fhirVersion),
                     null => message.WithNoBody()

src/Hl7.Fhir.Base/Rest/FhirClientSettings.cs

@@ -8,6 +8,7 @@
 
 #nullable enable
 
+using Hl7.Fhir.Model;
 using Hl7.Fhir.Serialization;
 using Hl7.Fhir.Utility;
 using System;
@@ -128,6 +129,17 @@ public bool CompressRequestBody
         /// </summary>
         public ParserSettings? ParserSettings = ParserSettings.CreateDefault();
 
+        /// <summary>
+        /// How to transfer binary data when sending data to a Binary endpoint.
+        /// </summary>
+        public BinaryTransferBehaviour BinarySendBehaviour = BinaryTransferBehaviour.UseData;
+
+        /// <summary>
+        /// How to transfer binary data when receiving data from a Binary endpoint.
+        /// </summary>
+        public BinaryTransferBehaviour BinaryReceiveBehaviour = BinaryTransferBehaviour.UseData;
+
+
         public FhirClientSettings() { }
 
         /// <summary>Clone constructor. Generates a new <see cref="FhirClientSettings"/> instance initialized from the state of the specified instance.</summary>
@@ -158,6 +170,8 @@ public void CopyTo(FhirClientSettings other)
             other.PreferredParameterHandling = PreferredParameterHandling;
             other.SerializationEngine = SerializationEngine;
             other.RequestBodyCompressionMethod = RequestBodyCompressionMethod;
+            other.BinaryReceiveBehaviour = BinaryReceiveBehaviour;
+            other.BinarySendBehaviour = BinarySendBehaviour;
         }
 
         /// <summary>Creates a new <see cref="FhirClientSettings"/> object that is a copy of the current instance.</summary>
@@ -166,6 +180,22 @@ public void CopyTo(FhirClientSettings other)
         /// <summary>Creates a new <see cref="FhirClientSettings"/> instance with default property values.</summary>
         public static FhirClientSettings CreateDefault() => new();
     }
+
+    /// <summary>
+    /// Describes how the client sends and receives data at the Binary endpoint.
+    /// </summary>
+    public enum BinaryTransferBehaviour
+    {
+        /// <summary>
+        /// Prefer to package binary data in a <see cref="Binary"/> resource.
+        /// </summary>
+        UseResource,
+
+        /// <summary>
+        /// Prefer to send and receive the binary data directly to and from the endpoint.
+        /// </summary>
+        UseData
+    }
 }
 
 #nullable restore

src/Hl7.Fhir.Base/Rest/HttpContentBuilders.cs

@@ -9,16 +9,15 @@
 #nullable enable
 
 using Hl7.Fhir.Model;
+using Hl7.Fhir.Serialization;
 using Hl7.Fhir.Utility;
+using System;
 using System.Collections.Generic;
+using System.Linq;
+using System.Net;
 using System.Net.Http;
 using System.Net.Http.Headers;
-using System.Linq;
-using Hl7.Fhir.Serialization;
-using System;
-using System.Text.Unicode;
 using System.Text;
-using System.Net;
 
 namespace Hl7.Fhir.Rest
 {
@@ -34,6 +33,7 @@ public static HttpContent CreateContentFromBinary(Binary b)
         {
             var content = new ByteArrayContent(b.Data ?? b.Content);
             content.Headers.ContentType = MediaTypeHeaderValue.Parse(b.ContentType);
+            content.Headers.LastModified = b.Meta?.LastUpdated;
 
             if (b.SecurityContext?.Reference is { } secRef)
                 content.Headers.Add(HttpUtil.SECURITYCONTEXT, secRef);