[wip]: Add XML Model Deserialization Support

docs/samples/client/csharp/SampleService/SampleClient/src/Generated/Models/SampleTypeSpecContext.cs

@@ -30,6 +30,9 @@ namespace SampleTypeSpec
     [ModelReaderWriterBuildable(typeof(Thing))]
     [ModelReaderWriterBuildable(typeof(UnknownAnimal))]
     [ModelReaderWriterBuildable(typeof(UnknownPet))]
+    [ModelReaderWriterBuildable(typeof(XmlAdvancedModel))]
+    [ModelReaderWriterBuildable(typeof(XmlItem))]
+    [ModelReaderWriterBuildable(typeof(XmlNestedModel))]
     public partial class SampleTypeSpecContext : ModelReaderWriterContext
     {
     }

docs/samples/client/csharp/SampleService/SampleClient/src/Generated/Models/XmlAdvancedModel.cs

@@ -0,0 +1,206 @@
+// <auto-generated/>
+
+#nullable disable
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace SampleTypeSpec
+{
+    /// <summary> An advanced XML model for testing various property types and XML features. </summary>
+    public partial class XmlAdvancedModel
+    {
+        /// <summary> Keeps track of any properties unknown to the library. </summary>
+        private protected readonly IDictionary<string, BinaryData> _additionalBinaryDataProperties;
+
+        /// <summary> Initializes a new instance of <see cref="XmlAdvancedModel"/>. </summary>
+        /// <param name="name"> A simple string property. </param>
+        /// <param name="age"> An integer property. </param>
+        /// <param name="enabled"> A boolean property. </param>
+        /// <param name="score"> A float property. </param>
+        /// <param name="nullableString"> A nullable string. </param>
+        /// <param name="id"> A string as XML attribute. </param>
+        /// <param name="version"> An integer as XML attribute. </param>
+        /// <param name="isActive"> A boolean as XML attribute. </param>
+        /// <param name="originalName"> A property with a custom XML element name. </param>
+        /// <param name="xmlIdentifier"> An attribute with a custom XML name. </param>
+        /// <param name="content"> Text content in the element (unwrapped string). </param>
+        /// <param name="unwrappedStrings"> An unwrapped array of strings - items appear directly without wrapper. </param>
+        /// <param name="unwrappedCounts"> An unwrapped array of integers. </param>
+        /// <param name="unwrappedItems"> An unwrapped array of models. </param>
+        /// <param name="wrappedColors"> A wrapped array of strings (default). </param>
+        /// <param name="items"> A wrapped array with custom wrapper name. </param>
+        /// <param name="nestedModel"> A nested model property. </param>
+        /// <param name="metadata"> A dictionary property. </param>
+        /// <param name="createdAt"> A date-time property. </param>
+        /// <param name="duration"> A duration property. </param>
+        /// <param name="data"> A bytes property. </param>
+        internal XmlAdvancedModel(string name, int age, bool enabled, float score, string nullableString, string id, int version, bool isActive, string originalName, string xmlIdentifier, string content, IEnumerable<string> unwrappedStrings, IEnumerable<int> unwrappedCounts, IEnumerable<XmlItem> unwrappedItems, IEnumerable<string> wrappedColors, IEnumerable<XmlItem> items, XmlNestedModel nestedModel, IDictionary<string, string> metadata, DateTimeOffset createdAt, TimeSpan duration, BinaryData data)
+        {
+            Name = name;
+            Age = age;
+            Enabled = enabled;
+            Score = score;
+            NullableString = nullableString;
+            Id = id;
+            Version = version;
+            IsActive = isActive;
+            OriginalName = originalName;
+            XmlIdentifier = xmlIdentifier;
+            Content = content;
+            UnwrappedStrings = unwrappedStrings.ToList();
+            UnwrappedCounts = unwrappedCounts.ToList();
+            UnwrappedItems = unwrappedItems.ToList();
+            WrappedColors = wrappedColors.ToList();
+            Items = items.ToList();
+            NestedModel = nestedModel;
+            Metadata = metadata;
+            CreatedAt = createdAt;
+            Duration = duration;
+            Data = data;
+        }
+
+        /// <summary> Initializes a new instance of <see cref="XmlAdvancedModel"/>. </summary>
+        /// <param name="name"> A simple string property. </param>
+        /// <param name="age"> An integer property. </param>
+        /// <param name="enabled"> A boolean property. </param>
+        /// <param name="score"> A float property. </param>
+        /// <param name="optionalString"> An optional string. </param>
+        /// <param name="optionalInt"> An optional integer. </param>
+        /// <param name="nullableString"> A nullable string. </param>
+        /// <param name="id"> A string as XML attribute. </param>
+        /// <param name="version"> An integer as XML attribute. </param>
+        /// <param name="isActive"> A boolean as XML attribute. </param>
+        /// <param name="originalName"> A property with a custom XML element name. </param>
+        /// <param name="xmlIdentifier"> An attribute with a custom XML name. </param>
+        /// <param name="content"> Text content in the element (unwrapped string). </param>
+        /// <param name="unwrappedStrings"> An unwrapped array of strings - items appear directly without wrapper. </param>
+        /// <param name="unwrappedCounts"> An unwrapped array of integers. </param>
+        /// <param name="unwrappedItems"> An unwrapped array of models. </param>
+        /// <param name="wrappedColors"> A wrapped array of strings (default). </param>
+        /// <param name="items"> A wrapped array with custom wrapper name. </param>
+        /// <param name="nestedModel"> A nested model property. </param>
+        /// <param name="optionalNestedModel"> An optional nested model. </param>
+        /// <param name="metadata"> A dictionary property. </param>
+        /// <param name="createdAt"> A date-time property. </param>
+        /// <param name="duration"> A duration property. </param>
+        /// <param name="data"> A bytes property. </param>
+        /// <param name="additionalBinaryDataProperties"> Keeps track of any properties unknown to the library. </param>
+        internal XmlAdvancedModel(string name, int age, bool enabled, float score, string optionalString, int? optionalInt, string nullableString, string id, int version, bool isActive, string originalName, string xmlIdentifier, string content, IList<string> unwrappedStrings, IList<int> unwrappedCounts, IList<XmlItem> unwrappedItems, IList<string> wrappedColors, IList<XmlItem> items, XmlNestedModel nestedModel, XmlNestedModel optionalNestedModel, IDictionary<string, string> metadata, DateTimeOffset createdAt, TimeSpan duration, BinaryData data, IDictionary<string, BinaryData> additionalBinaryDataProperties)
+        {
+            Name = name;
+            Age = age;
+            Enabled = enabled;
+            Score = score;
+            OptionalString = optionalString;
+            OptionalInt = optionalInt;
+            NullableString = nullableString;
+            Id = id;
+            Version = version;
+            IsActive = isActive;
+            OriginalName = originalName;
+            XmlIdentifier = xmlIdentifier;
+            Content = content;
+            UnwrappedStrings = unwrappedStrings;
+            UnwrappedCounts = unwrappedCounts;
+            UnwrappedItems = unwrappedItems;
+            WrappedColors = wrappedColors;
+            Items = items;
+            NestedModel = nestedModel;
+            OptionalNestedModel = optionalNestedModel;
+            Metadata = metadata;
+            CreatedAt = createdAt;
+            Duration = duration;
+            Data = data;
+            _additionalBinaryDataProperties = additionalBinaryDataProperties;
+        }
+
+        /// <summary> A simple string property. </summary>
+        public string Name { get; }
+
+        /// <summary> An integer property. </summary>
+        public int Age { get; }
+
+        /// <summary> A boolean property. </summary>
+        public bool Enabled { get; }
+
+        /// <summary> A float property. </summary>
+        public float Score { get; }
+
+        /// <summary> An optional string. </summary>
+        public string OptionalString { get; }
+
+        /// <summary> An optional integer. </summary>
+        public int? OptionalInt { get; }
+
+        /// <summary> A nullable string. </summary>
+        public string NullableString { get; }
+
+        /// <summary> A string as XML attribute. </summary>
+        public string Id { get; }
+
+        /// <summary> An integer as XML attribute. </summary>
+        public int Version { get; }
+
+        /// <summary> A boolean as XML attribute. </summary>
+        public bool IsActive { get; }
+
+        /// <summary> A property with a custom XML element name. </summary>
+        public string OriginalName { get; }
+
+        /// <summary> An attribute with a custom XML name. </summary>
+        public string XmlIdentifier { get; }
+
+        /// <summary> Text content in the element (unwrapped string). </summary>
+        public string Content { get; }
+
+        /// <summary> An unwrapped array of strings - items appear directly without wrapper. </summary>
+        public IList<string> UnwrappedStrings { get; }
+
+        /// <summary> An unwrapped array of integers. </summary>
+        public IList<int> UnwrappedCounts { get; }
+
+        /// <summary> An unwrapped array of models. </summary>
+        public IList<XmlItem> UnwrappedItems { get; }
+
+        /// <summary> A wrapped array of strings (default). </summary>
+        public IList<string> WrappedColors { get; }
+
+        /// <summary> A wrapped array with custom wrapper name. </summary>
+        public IList<XmlItem> Items { get; }
+
+        /// <summary> A nested model property. </summary>
+        public XmlNestedModel NestedModel { get; }
+
+        /// <summary> An optional nested model. </summary>
+        public XmlNestedModel OptionalNestedModel { get; }
+
+        /// <summary> A dictionary property. </summary>
+        public IDictionary<string, string> Metadata { get; }
+
+        /// <summary> A date-time property. </summary>
+        public DateTimeOffset CreatedAt { get; }
+
+        /// <summary> A duration property. </summary>
+        public TimeSpan Duration { get; }
+
+        /// <summary>
+        /// A bytes property
+        /// <para>
+        /// To assign a byte[] to this property use <see cref="BinaryData.FromBytes(byte[])"/>.
+        /// The byte[] will be serialized to a Base64 encoded string.
+        /// </para>
+        /// <para>
+        /// Examples:
+        /// <list type="bullet">
+        /// <item>
+        /// <term> BinaryData.FromBytes(new byte[] { 1, 2, 3 }). </term>
+        /// <description> Creates a payload of "AQID". </description>
+        /// </item>
+        /// </list>
+        /// </para>
+        /// </summary>
+        public BinaryData Data { get; }
+    }
+}

docs/samples/client/csharp/SampleService/SampleClient/src/Generated/Models/XmlItem.Serialization.cs

@@ -0,0 +1,155 @@
+// <auto-generated/>
+
+#nullable disable
+
+using System;
+using System.ClientModel.Primitives;
+using System.Collections.Generic;
+using System.Text.Json;
+
+namespace SampleTypeSpec
+{
+    /// <summary> An item model for XML array testing. </summary>
+    public partial class XmlItem : IJsonModel<XmlItem>
+    {
+        /// <summary> Initializes a new instance of <see cref="XmlItem"/> for deserialization. </summary>
+        internal XmlItem()
+        {
+        }
+
+        /// <param name="writer"> The JSON writer. </param>
+        /// <param name="options"> The client options for reading and writing models. </param>
+        void IJsonModel<XmlItem>.Write(Utf8JsonWriter writer, ModelReaderWriterOptions options)
+        {
+            writer.WriteStartObject();
+            JsonModelWriteCore(writer, options);
+            writer.WriteEndObject();
+        }
+
+        /// <param name="writer"> The JSON writer. </param>
+        /// <param name="options"> The client options for reading and writing models. </param>
+        protected virtual void JsonModelWriteCore(Utf8JsonWriter writer, ModelReaderWriterOptions options)
+        {
+            string format = options.Format == "W" ? ((IPersistableModel<XmlItem>)this).GetFormatFromOptions(options) : options.Format;
+            if (format != "J")
+            {
+                throw new FormatException($"The model {nameof(XmlItem)} does not support writing '{format}' format.");
+            }
+            writer.WritePropertyName("itemName"u8);
+            writer.WriteStringValue(ItemName);
+            writer.WritePropertyName("itemValue"u8);
+            writer.WriteNumberValue(ItemValue);
+            writer.WritePropertyName("itemId"u8);
+            writer.WriteStringValue(ItemId);
+            if (options.Format != "W" && _additionalBinaryDataProperties != null)
+            {
+                foreach (var item in _additionalBinaryDataProperties)
+                {
+                    writer.WritePropertyName(item.Key);
+#if NET6_0_OR_GREATER
+                    writer.WriteRawValue(item.Value);
+#else
+                    using (JsonDocument document = JsonDocument.Parse(item.Value))
+                    {
+                        JsonSerializer.Serialize(writer, document.RootElement);
+                    }
+#endif
+                }
+            }
+        }
+
+        /// <param name="reader"> The JSON reader. </param>
+        /// <param name="options"> The client options for reading and writing models. </param>
+        XmlItem IJsonModel<XmlItem>.Create(ref Utf8JsonReader reader, ModelReaderWriterOptions options) => JsonModelCreateCore(ref reader, options);
+
+        /// <param name="reader"> The JSON reader. </param>
+        /// <param name="options"> The client options for reading and writing models. </param>
+        protected virtual XmlItem JsonModelCreateCore(ref Utf8JsonReader reader, ModelReaderWriterOptions options)
+        {
+            string format = options.Format == "W" ? ((IPersistableModel<XmlItem>)this).GetFormatFromOptions(options) : options.Format;
+            if (format != "J")
+            {
+                throw new FormatException($"The model {nameof(XmlItem)} does not support reading '{format}' format.");
+            }
+            using JsonDocument document = JsonDocument.ParseValue(ref reader);
+            return DeserializeXmlItem(document.RootElement, options);
+        }
+
+        /// <param name="element"> The JSON element to deserialize. </param>
+        /// <param name="options"> The client options for reading and writing models. </param>
+        internal static XmlItem DeserializeXmlItem(JsonElement element, ModelReaderWriterOptions options)
+        {
+            if (element.ValueKind == JsonValueKind.Null)
+            {
+                return null;
+            }
+            string itemName = default;
+            int itemValue = default;
+            string itemId = default;
+            IDictionary<string, BinaryData> additionalBinaryDataProperties = new ChangeTrackingDictionary<string, BinaryData>();
+            foreach (var prop in element.EnumerateObject())
+            {
+                if (prop.NameEquals("itemName"u8))
+                {
+                    itemName = prop.Value.GetString();
+                    continue;
+                }
+                if (prop.NameEquals("itemValue"u8))
+                {
+                    itemValue = prop.Value.GetInt32();
+                    continue;
+                }
+                if (prop.NameEquals("itemId"u8))
+                {
+                    itemId = prop.Value.GetString();
+                    continue;
+                }
+                if (options.Format != "W")
+                {
+                    additionalBinaryDataProperties.Add(prop.Name, BinaryData.FromString(prop.Value.GetRawText()));
+                }
+            }
+            return new XmlItem(itemName, itemValue, itemId, additionalBinaryDataProperties);
+        }
+
+        /// <param name="options"> The client options for reading and writing models. </param>
+        BinaryData IPersistableModel<XmlItem>.Write(ModelReaderWriterOptions options) => PersistableModelWriteCore(options);
+
+        /// <param name="options"> The client options for reading and writing models. </param>
+        protected virtual BinaryData PersistableModelWriteCore(ModelReaderWriterOptions options)
+        {
+            string format = options.Format == "W" ? ((IPersistableModel<XmlItem>)this).GetFormatFromOptions(options) : options.Format;
+            switch (format)
+            {
+                case "J":
+                    return ModelReaderWriter.Write(this, options, SampleTypeSpecContext.Default);
+                default:
+                    throw new FormatException($"The model {nameof(XmlItem)} does not support writing '{options.Format}' format.");
+            }
+        }
+
+        /// <param name="data"> The data to parse. </param>
+        /// <param name="options"> The client options for reading and writing models. </param>
+        XmlItem IPersistableModel<XmlItem>.Create(BinaryData data, ModelReaderWriterOptions options) => PersistableModelCreateCore(data, options);
+
+        /// <param name="data"> The data to parse. </param>
+        /// <param name="options"> The client options for reading and writing models. </param>
+        protected virtual XmlItem PersistableModelCreateCore(BinaryData data, ModelReaderWriterOptions options)
+        {
+            string format = options.Format == "W" ? ((IPersistableModel<XmlItem>)this).GetFormatFromOptions(options) : options.Format;
+            switch (format)
+            {
+                case "J":
+                    using (JsonDocument document = JsonDocument.Parse(data))
+                    {
+                        return DeserializeXmlItem(document.RootElement, options);
+                    }
+                default:
+                    throw new FormatException($"The model {nameof(XmlItem)} does not support reading '{options.Format}' format.");
+            }
+        }
+
+        /// <param name="options"> The client options for reading and writing models. </param>
+        string IPersistableModel<XmlItem>.GetFormatFromOptions(ModelReaderWriterOptions options) => "J";
+    }
+}