Fix XML serialization in convenience methods for dual-format models

docs/samples/client/csharp/SampleService/SampleClient/src/Generated/PlantOperations.RestClient.cs

@@ -26,6 +26,18 @@ internal PipelineMessage CreateGetTreeRequest(RequestOptions options)
             return message;
         }
 
+        internal PipelineMessage CreateGetTreeAsJsonRequest(RequestOptions options)
+        {
+            ClientUriBuilder uri = new ClientUriBuilder();
+            uri.Reset(_endpoint);
+            uri.AppendPath("/plants/tree/as-plant/json", false);
+            PipelineMessage message = Pipeline.CreateMessage(uri.ToUri(), "GET", PipelineMessageClassifier200);
+            PipelineRequest request = message.Request;
+            request.Headers.Set("Accept", "application/json");
+            message.Apply(options);
+            return message;
+        }
+
         internal PipelineMessage CreateUpdateTreeRequest(BinaryContent content, RequestOptions options)
         {
             ClientUriBuilder uri = new ClientUriBuilder();
@@ -39,5 +51,19 @@ internal PipelineMessage CreateUpdateTreeRequest(BinaryContent content, RequestO
             message.Apply(options);
             return message;
         }
+
+        internal PipelineMessage CreateUpdateTreeAsJsonRequest(BinaryContent content, RequestOptions options)
+        {
+            ClientUriBuilder uri = new ClientUriBuilder();
+            uri.Reset(_endpoint);
+            uri.AppendPath("/plants/tree/as-plant/json", false);
+            PipelineMessage message = Pipeline.CreateMessage(uri.ToUri(), "PUT", PipelineMessageClassifier200);
+            PipelineRequest request = message.Request;
+            request.Headers.Set("Content-Type", "application/json");
+            request.Headers.Set("Accept", "application/json");
+            request.Content = content;
+            message.Apply(options);
+            return message;
+        }
     }
 }

docs/samples/client/csharp/SampleService/SampleClient/src/Generated/PlantOperations.cs

@@ -136,6 +136,110 @@ public virtual async Task<ClientResult<Tree>> GetTreeAsync(CancellationToken can
             }
         }
 
+        /// <summary>
+        /// [Protocol Method] Get a tree as a plant
+        /// <list type="bullet">
+        /// <item>
+        /// <description> This <see href="https://aka.ms/azsdk/net/protocol-methods">protocol method</see> allows explicit creation of the request and processing of the response for advanced scenarios. </description>
+        /// </item>
+        /// </list>
+        /// </summary>
+        /// <param name="options"> The request options, which can override default behaviors of the client pipeline on a per-call basis. </param>
+        /// <exception cref="ClientResultException"> Service returned a non-success status code. </exception>
+        /// <returns> The response returned from the service. </returns>
+        public virtual ClientResult GetTreeAsJson(RequestOptions options)
+        {
+            try
+            {
+                System.Console.WriteLine("Entering method GetTreeAsJson.");
+                using PipelineMessage message = CreateGetTreeAsJsonRequest(options);
+                return ClientResult.FromResponse(Pipeline.ProcessMessage(message, options));
+            }
+            catch (Exception ex)
+            {
+                System.Console.WriteLine($"An exception was thrown in method GetTreeAsJson: {ex}");
+                throw;
+            }
+            finally
+            {
+                System.Console.WriteLine("Exiting method GetTreeAsJson.");
+            }
+        }
+
+        /// <summary>
+        /// [Protocol Method] Get a tree as a plant
+        /// <list type="bullet">
+        /// <item>
+        /// <description> This <see href="https://aka.ms/azsdk/net/protocol-methods">protocol method</see> allows explicit creation of the request and processing of the response for advanced scenarios. </description>
+        /// </item>
+        /// </list>
+        /// </summary>
+        /// <param name="options"> The request options, which can override default behaviors of the client pipeline on a per-call basis. </param>
+        /// <exception cref="ClientResultException"> Service returned a non-success status code. </exception>
+        /// <returns> The response returned from the service. </returns>
+        public virtual async Task<ClientResult> GetTreeAsJsonAsync(RequestOptions options)
+        {
+            try
+            {
+                System.Console.WriteLine("Entering method GetTreeAsJsonAsync.");
+                using PipelineMessage message = CreateGetTreeAsJsonRequest(options);
+                return ClientResult.FromResponse(await Pipeline.ProcessMessageAsync(message, options).ConfigureAwait(false));
+            }
+            catch (Exception ex)
+            {
+                System.Console.WriteLine($"An exception was thrown in method GetTreeAsJsonAsync: {ex}");
+                throw;
+            }
+            finally
+            {
+                System.Console.WriteLine("Exiting method GetTreeAsJsonAsync.");
+            }
+        }
+
+        /// <summary> Get a tree as a plant. </summary>
+        /// <param name="cancellationToken"> The cancellation token that can be used to cancel the operation. </param>
+        /// <exception cref="ClientResultException"> Service returned a non-success status code. </exception>
+        public virtual ClientResult<Tree> GetTreeAsJson(CancellationToken cancellationToken = default)
+        {
+            try
+            {
+                System.Console.WriteLine("Entering method GetTreeAsJson.");
+                ClientResult result = GetTreeAsJson(cancellationToken.ToRequestOptions());
+                return ClientResult.FromValue((Tree)result, result.GetRawResponse());
+            }
+            catch (Exception ex)
+            {
+                System.Console.WriteLine($"An exception was thrown in method GetTreeAsJson: {ex}");
+                throw;
+            }
+            finally
+            {
+                System.Console.WriteLine("Exiting method GetTreeAsJson.");
+            }
+        }
+
+        /// <summary> Get a tree as a plant. </summary>
+        /// <param name="cancellationToken"> The cancellation token that can be used to cancel the operation. </param>
+        /// <exception cref="ClientResultException"> Service returned a non-success status code. </exception>
+        public virtual async Task<ClientResult<Tree>> GetTreeAsJsonAsync(CancellationToken cancellationToken = default)
+        {
+            try
+            {
+                System.Console.WriteLine("Entering method GetTreeAsJsonAsync.");
+                ClientResult result = await GetTreeAsJsonAsync(cancellationToken.ToRequestOptions()).ConfigureAwait(false);
+                return ClientResult.FromValue((Tree)result, result.GetRawResponse());
+            }
+            catch (Exception ex)
+            {
+                System.Console.WriteLine($"An exception was thrown in method GetTreeAsJsonAsync: {ex}");
+                throw;
+            }
+            finally
+            {
+                System.Console.WriteLine("Exiting method GetTreeAsJsonAsync.");
+            }
+        }
+
         /// <summary>
         /// [Protocol Method] Update a tree as a plant
         /// <list type="bullet">
@@ -255,5 +359,125 @@ public virtual async Task<ClientResult<Tree>> UpdateTreeAsync(Tree tree, Cancell
                 System.Console.WriteLine("Exiting method UpdateTreeAsync.");
             }
         }
+
+        /// <summary>
+        /// [Protocol Method] Update a tree as a plant
+        /// <list type="bullet">
+        /// <item>
+        /// <description> This <see href="https://aka.ms/azsdk/net/protocol-methods">protocol method</see> allows explicit creation of the request and processing of the response for advanced scenarios. </description>
+        /// </item>
+        /// </list>
+        /// </summary>
+        /// <param name="content"> The content to send as the body of the request. </param>
+        /// <param name="options"> The request options, which can override default behaviors of the client pipeline on a per-call basis. </param>
+        /// <exception cref="ArgumentNullException"> <paramref name="content"/> is null. </exception>
+        /// <exception cref="ClientResultException"> Service returned a non-success status code. </exception>
+        /// <returns> The response returned from the service. </returns>
+        public virtual ClientResult UpdateTreeAsJson(BinaryContent content, RequestOptions options = null)
+        {
+            try
+            {
+                System.Console.WriteLine("Entering method UpdateTreeAsJson.");
+                Argument.AssertNotNull(content, nameof(content));
+
+                using PipelineMessage message = CreateUpdateTreeAsJsonRequest(content, options);
+                return ClientResult.FromResponse(Pipeline.ProcessMessage(message, options));
+            }
+            catch (Exception ex)
+            {
+                System.Console.WriteLine($"An exception was thrown in method UpdateTreeAsJson: {ex}");
+                throw;
+            }
+            finally
+            {
+                System.Console.WriteLine("Exiting method UpdateTreeAsJson.");
+            }
+        }
+
+        /// <summary>
+        /// [Protocol Method] Update a tree as a plant
+        /// <list type="bullet">
+        /// <item>
+        /// <description> This <see href="https://aka.ms/azsdk/net/protocol-methods">protocol method</see> allows explicit creation of the request and processing of the response for advanced scenarios. </description>
+        /// </item>
+        /// </list>
+        /// </summary>
+        /// <param name="content"> The content to send as the body of the request. </param>
+        /// <param name="options"> The request options, which can override default behaviors of the client pipeline on a per-call basis. </param>
+        /// <exception cref="ArgumentNullException"> <paramref name="content"/> is null. </exception>
+        /// <exception cref="ClientResultException"> Service returned a non-success status code. </exception>
+        /// <returns> The response returned from the service. </returns>
+        public virtual async Task<ClientResult> UpdateTreeAsJsonAsync(BinaryContent content, RequestOptions options = null)
+        {
+            try
+            {
+                System.Console.WriteLine("Entering method UpdateTreeAsJsonAsync.");
+                Argument.AssertNotNull(content, nameof(content));
+
+                using PipelineMessage message = CreateUpdateTreeAsJsonRequest(content, options);
+                return ClientResult.FromResponse(await Pipeline.ProcessMessageAsync(message, options).ConfigureAwait(false));
+            }
+            catch (Exception ex)
+            {
+                System.Console.WriteLine($"An exception was thrown in method UpdateTreeAsJsonAsync: {ex}");
+                throw;
+            }
+            finally
+            {
+                System.Console.WriteLine("Exiting method UpdateTreeAsJsonAsync.");
+            }
+        }
+
+        /// <summary> Update a tree as a plant. </summary>
+        /// <param name="tree"></param>
+        /// <param name="cancellationToken"> The cancellation token that can be used to cancel the operation. </param>
+        /// <exception cref="ArgumentNullException"> <paramref name="tree"/> is null. </exception>
+        /// <exception cref="ClientResultException"> Service returned a non-success status code. </exception>
+        public virtual ClientResult<Tree> UpdateTreeAsJson(Tree tree, CancellationToken cancellationToken = default)
+        {
+            try
+            {
+                System.Console.WriteLine("Entering method UpdateTreeAsJson.");
+                Argument.AssertNotNull(tree, nameof(tree));
+
+                ClientResult result = UpdateTreeAsJson(tree, cancellationToken.ToRequestOptions());
+                return ClientResult.FromValue((Tree)result, result.GetRawResponse());
+            }
+            catch (Exception ex)
+            {
+                System.Console.WriteLine($"An exception was thrown in method UpdateTreeAsJson: {ex}");
+                throw;
+            }
+            finally
+            {
+                System.Console.WriteLine("Exiting method UpdateTreeAsJson.");
+            }
+        }
+
+        /// <summary> Update a tree as a plant. </summary>
+        /// <param name="tree"></param>
+        /// <param name="cancellationToken"> The cancellation token that can be used to cancel the operation. </param>
+        /// <exception cref="ArgumentNullException"> <paramref name="tree"/> is null. </exception>
+        /// <exception cref="ClientResultException"> Service returned a non-success status code. </exception>
+        public virtual async Task<ClientResult<Tree>> UpdateTreeAsJsonAsync(Tree tree, CancellationToken cancellationToken = default)
+        {
+            try
+            {
+                System.Console.WriteLine("Entering method UpdateTreeAsJsonAsync.");
+                Argument.AssertNotNull(tree, nameof(tree));
+
+                ClientResult result = await UpdateTreeAsJsonAsync(tree, cancellationToken.ToRequestOptions()).ConfigureAwait(false);
+                return ClientResult.FromValue((Tree)result, result.GetRawResponse());
+            }
+            catch (Exception ex)
+            {
+                System.Console.WriteLine($"An exception was thrown in method UpdateTreeAsJsonAsync: {ex}");
+                throw;
+            }
+            finally
+            {
+                System.Console.WriteLine("Exiting method UpdateTreeAsJsonAsync.");
+            }
+        }
     }
 }

docs/samples/client/csharp/SampleService/main.tsp

@@ -791,7 +791,6 @@ model Plant {
 }
 
 @doc("Tree is a specific type of plant")
-@usage(Usage.xml | Usage.output | Usage.json)
 model Tree extends Plant {
   species: "tree";
 
@@ -809,13 +808,29 @@ interface PlantOperations {
     @body body: Tree;
   };
 
+  @doc("Get a tree as a plant")
+  @get
+  @route("/tree/as-plant/json")
+  getTreeAsJson(): {
+    @header contentType: "application/json";
+    @body body: Tree;
+  };
+
   @doc("Update a tree as a plant")
   @put
   @route("/tree/as-plant")
   updateTree(@body tree: Tree, @header contentType: "application/xml"): {
     @header contentType: "application/xml";
     @body body: Tree;
   };
+
+  @doc("Update a tree as a plant")
+  @put
+  @route("/tree/as-plant/json")
+  updateTreeAsJson(@body tree: Tree, @header contentType: "application/json"): {
+    @header contentType: "application/json";
+    @body body: Tree;
+  };
 }
 
 @clientInitialization({

packages/http-client-csharp/generator/Microsoft.TypeSpec.Generator.ClientModel/src/Providers/MrwSerializationTypeDefinition.cs

@@ -193,6 +193,11 @@ protected override MethodProvider[] BuildMethods()
                     if (ScmCodeModelGenerator.Instance.TypeFactory.RootInputModels.Contains(_inputModel))
                     {
                         methods.Add(BuildImplicitToBinaryContent());
+                        // Add internal ToBinaryContent helper for format-specific serialization
+                        if (_supportsJson && _supportsXml)
+                        {
+                            methods.Add(BuildToBinaryContentMethod());
+                        }
                     }
 
                     if (ScmCodeModelGenerator.Instance.TypeFactory.RootOutputModels.Contains(_inputModel))
@@ -326,6 +331,23 @@ private MethodProvider BuildImplicitToBinaryContent()
                 this);
         }
 
+        private MethodProvider BuildToBinaryContentMethod()
+        {
+            var formatParameter = new ParameterProvider("format", $"The format to use for serialization", typeof(string));
+
+            // ModelReaderWriterOptions options = new ModelReaderWriterOptions(format);
+            // return BinaryContent.Create(this, options);
+            var requestContentType = ScmCodeModelGenerator.Instance.TypeFactory.RequestContentApi.RequestContentType;
+            return new MethodProvider(
+                new MethodSignature($"To{requestContentType.Name}", FormattableStringHelpers.FromString($"Converts the model to {requestContentType.Name} using the specified format"), MethodSignatureModifiers.Internal, requestContentType, null, [formatParameter]),
+                new MethodBodyStatement[]
+                {
+                    Declare("options", typeof(ModelReaderWriterOptions), New.Instance(typeof(ModelReaderWriterOptions), formatParameter), out var options),
+                    Return(RequestContentApiSnippets.Create(This, options.As<ModelReaderWriterOptions>()))
+                },
+                this);
+        }
+
         /// <summary>
         /// Builds the types that the model type serialization implements.
         /// </summary>