New approach to CSHARP-284 and CSHARP-308. Serialization attributes are just another way of setting serialization options and are now processed by the options themselves in the new ApplyAttribute method. Serialization options now have a few new methods: ApplyAttribute, Clone and Freeze. Removed IsItemsOption and ItemSerializationOptionsWrapper; whether an attribute is for the container or for the items is determined by context. Introduced new BsonBaseSerializationOptions class to make implementing serialization options easier. All serializers that use serialization options now return the default serialization options from the new GetDefaultSerializationOptions method. There are minute changes to the unit tests; that is a good thing as it implies these changes are not breaking changes.

Author: rstam

Bson/Bson.csproj

@@ -99,7 +99,8 @@
     <Compile Include="Serialization\Conventions\ExtraElementsMemberConventions.cs" />
     <Compile Include="Serialization\Conventions\IgnoreIfDefaultConventions.cs" />
     <Compile Include="Serialization\Conventions\SerializationOptionsConventions.cs" />
-    <Compile Include="Serialization\Options\ItemSerializationOptionsWrapper.cs" />
+    <Compile Include="Serialization\Options\ArraySerializationOptions.cs" />
+    <Compile Include="Serialization\Options\BsonBaseSerializationOptions.cs" />
     <Compile Include="Serialization\Options\DateTimeSerializationOptions.cs" />
     <Compile Include="Serialization\Options\DictionarySerializationOptions.cs" />
     <Compile Include="Serialization\Options\DocumentSerializationOptions.cs" />

Bson/ObjectModel/BsonDocument.cs

@@ -1007,11 +1007,19 @@ public void RemoveElement(BsonElement element)
         /// <param name="options">The serialization options (can be null).</param>
         public void Serialize(BsonWriter bsonWriter, Type nominalType, IBsonSerializationOptions options)
         {
-            bsonWriter.WriteStartDocument();
+            var documentSerializationOptions = (options ?? DocumentSerializationOptions.Defaults) as DocumentSerializationOptions;
+            if (documentSerializationOptions == null)
+            {
+                var message = string.Format(
+                    "Serialize method of BsonDocument expected serialization options of type {0}, not {1}.",
+                    BsonUtils.GetFriendlyTypeName(typeof(DocumentSerializationOptions)),
+                    BsonUtils.GetFriendlyTypeName(options.GetType()));
+                throw new BsonSerializationException(message);
+            }
 
-            var documentOptions = (options == null) ? DocumentSerializationOptions.Defaults : (DocumentSerializationOptions)options;
+            bsonWriter.WriteStartDocument();
             int idIndex;
-            if (documentOptions.SerializeIdFirst && _indexes.TryGetValue("_id", out idIndex))
+            if (documentSerializationOptions.SerializeIdFirst && _indexes.TryGetValue("_id", out idIndex))
             {
                 _elements[idIndex].WriteTo(bsonWriter);
             }

Bson/Serialization/Attributes/BsonDateTimeOptionsAttribute.cs

@@ -69,24 +69,5 @@ public BsonType Representation
             get { return _representation; }
             set { _representation = value; }
         }
-
-        // public methods
-        /// <summary>
-        /// Gets the serialization options specified by this attribute.
-        /// </summary>
-        /// <returns>The serialization options.</returns>
-        public override IBsonSerializationOptions GetOptions()
-        {
-            IBsonSerializationOptions serializationOptions;
-            if (_dateOnly)
-            {
-                serializationOptions = new DateTimeSerializationOptions(_dateOnly, _representation);
-            }
-            else
-            {
-                serializationOptions = new DateTimeSerializationOptions(_kind, _representation);
-            }
-            return CheckIfIsItemsOptions(serializationOptions);
-        }
     }
 }

Bson/Serialization/Attributes/BsonDefaultValueAttribute.cs

@@ -24,7 +24,7 @@ namespace MongoDB.Bson.Serialization.Attributes
     /// Specifies the default value for a field or property.
     /// </summary>
     [AttributeUsage(AttributeTargets.Property | AttributeTargets.Field)]
-    public class BsonDefaultValueAttribute : Attribute
+    public class BsonDefaultValueAttribute : BsonSerializationOptionsAttribute
     {
         // private fields
         private object _defaultValue;

Bson/Serialization/Attributes/BsonDictionaryOptionsAttribute.cs

@@ -58,16 +58,5 @@ public DictionaryRepresentation Representation
             get { return _representation; }
             set { _representation = value; }
         }
-
-        // public methods
-        /// <summary>
-        /// Gets the serialization options specified by this attribute.
-        /// </summary>
-        /// <returns>The serialization options.</returns>
-        public override IBsonSerializationOptions GetOptions()
-        {
-            var serializationOptions = new DictionarySerializationOptions(_representation);
-            return CheckIfIsItemsOptions(serializationOptions);
-        }
     }
 }

Bson/Serialization/Attributes/BsonDiscriminatorAttribute.cs

@@ -24,7 +24,7 @@ namespace MongoDB.Bson.Serialization.Attributes
     /// Specifies the discriminator and related options for a class.
     /// </summary>
     [AttributeUsage(AttributeTargets.Class | AttributeTargets.Struct)]
-    public class BsonDiscriminatorAttribute : Attribute
+    public class BsonDiscriminatorAttribute : BsonSerializationOptionsAttribute
     {
         // private fields
         private string _discriminator;

Bson/Serialization/Attributes/BsonElementAttribute.cs

@@ -24,7 +24,7 @@ namespace MongoDB.Bson.Serialization.Attributes
     /// Specifies the element name and related options for a field or property.
     /// </summary>
     [AttributeUsage(AttributeTargets.Property | AttributeTargets.Field)]
-    public class BsonElementAttribute : Attribute
+    public class BsonElementAttribute : BsonSerializationOptionsAttribute
     {
         // private fields
         private string _elementName;

Bson/Serialization/Attributes/BsonExtraElementsAttribute.cs

@@ -24,7 +24,7 @@ namespace MongoDB.Bson.Serialization.Attributes
     /// Indicates that extra elements should be ignored when this class is deserialized.
     /// </summary>
     [AttributeUsage(AttributeTargets.Property | AttributeTargets.Field)]
-    public class BsonExtraElementsAttribute : Attribute
+    public class BsonExtraElementsAttribute : BsonSerializationOptionsAttribute
     {
     }
 }

Bson/Serialization/Attributes/BsonIdAttribute.cs

@@ -24,7 +24,7 @@ namespace MongoDB.Bson.Serialization.Attributes
     /// Specifies that this is the Id field or property.
     /// </summary>
     [AttributeUsage(AttributeTargets.Property | AttributeTargets.Field)]
-    public class BsonIdAttribute : Attribute
+    public class BsonIdAttribute : BsonSerializationOptionsAttribute
     {
         // private fields
         private Type _idGenerator;

Bson/Serialization/Attributes/BsonIgnoreAttribute.cs

@@ -24,7 +24,7 @@ namespace MongoDB.Bson.Serialization.Attributes
     /// Indicates that this field or property should be ignored when this class is serialized.
     /// </summary>
     [AttributeUsage(AttributeTargets.Property | AttributeTargets.Field)]
-    public class BsonIgnoreAttribute : Attribute
+    public class BsonIgnoreAttribute : BsonSerializationOptionsAttribute
     {
     }
 }