Xml Shape Serializer - Schema serde

src/aws-cpp-sdk-core/include/smithy/client/schema/Schema.h

@@ -1,6 +1,7 @@
 #pragma once
 
 #include <aws/core/utils/memory/stl/AWSString.h>
+#include <smithy/client/schema/XmlTraits.h>
 
 #include <cstdint>
 
@@ -48,13 +49,23 @@ class Schema {
 
   uint16_t GetMemberCount() const { return m_memberCount; }
 
+  // XML traits accessor
+  const XmlTraits* GetXmlTraits() const { return m_xmlTraits; }
+
+  // Builder-style setter for XML traits pointer (used by codegen)
+  Schema& WithXmlTraits(const XmlTraits* traits) {
+    m_xmlTraits = traits;
+    return *this;
+  }
+
  private:
   const char* m_id = nullptr;
   ShapeType m_type = ShapeType::Structure;
   Aws::String m_memberName;
   int m_memberIndex = 0;
   const Schema* m_members = nullptr;
   uint16_t m_memberCount = 0;
+  const XmlTraits* m_xmlTraits = nullptr;
 };
 
 }  // namespace schema

src/aws-cpp-sdk-core/include/smithy/client/schema/XmlShapeSerializer.h

@@ -1,5 +1,6 @@
 #pragma once
 
+#include <aws/core/client/AWSError.h>
 #include <aws/core/utils/memory/AWSMemory.h>
 #include <smithy/Smithy_EXPORTS.h>
 #include <smithy/client/schema/ShapeSerializer.h>
@@ -9,6 +10,7 @@ namespace schema {
 
 class SMITHY_API XmlShapeSerializer final : public ShapeSerializer {
  public:
+  using SerializerOutcome = Aws::Utils::Outcome<Aws::String, Aws::Client::AWSError<Aws::Client::CoreErrors>>;
   XmlShapeSerializer();
   ~XmlShapeSerializer();
 
@@ -25,6 +27,8 @@ class SMITHY_API XmlShapeSerializer final : public ShapeSerializer {
   void WriteEnum(const Schema& schema, int value) override;
   void WriteNull(const Schema& schema) override;
 
+  void WriteAttribute(const Schema& schema, const Aws::String& value);
+
   bool BeginList(const Schema& schema, size_t count) override;
   void EndList() override;
 
@@ -35,7 +39,7 @@ class SMITHY_API XmlShapeSerializer final : public ShapeSerializer {
   bool BeginNestedStructure(const Schema& schema) override;
   void EndNestedStructure() override;
 
-  Aws::String GetPayload() const;
+  SerializerOutcome GetPayload();
 
  private:
   class Impl;

src/aws-cpp-sdk-core/include/smithy/client/schema/XmlTraits.h

@@ -0,0 +1,30 @@
+/**
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0.
+ */
+#pragma once
+
+#include <aws/core/utils/memory/stl/AWSString.h>
+
+namespace smithy {
+namespace schema {
+
+/**
+ * XML-specific traits for a Schema member.
+ * Instances should be declared as static const and referenced via pointer from Schema.
+ * Zero cost for non-XML services (Schema just holds a null pointer).
+ */
+struct XmlTraits {
+  Aws::String xmlName;          // @xmlName override (empty = use member name)
+  Aws::String listItemName;     // element name for list items (default: "member")
+  Aws::String mapEntryName;     // element name for map entries (default: "entry")
+  Aws::String mapKeyName;       // element name for map keys (default: "key")
+  Aws::String mapValueName;     // element name for map values (default: "value")
+  Aws::String namespaceUri;     // @xmlNamespace URI
+  Aws::String namespacePrefix;  // @xmlNamespace prefix (empty = default namespace)
+  bool flattened = false;       // @xmlFlattened
+  bool isAttribute = false;     // @xmlAttribute
+};
+
+}  // namespace schema
+}  // namespace smithy