Implement Mixed data type

CHANGELOG.md

@@ -25,6 +25,24 @@
   var obj = new MyObject();
   obj.Denominations.Add("quarter", 0.25d);
   ```
+* Add support for `RealmValue` data type. This new type can represent any valid Realm data type, including objects. Collections (lists, sets and dictionaries) of `RealmValue` are also supported, but 'RealmValue' cannot contain collections. Please note that a property of type `RealmValue` cannot be nullable, but can contain null, represented by the value `RealmValue.Null`. (PR [#2252](https://github.com/realm/realm-dotnet/pull/2252))   
+
+  ```csharp
+  public class MyObject : RealmObject
+  {
+      public RealmValue MyValue { get; set; }
+  }
+
+  var obj = new MyObject();
+  obj.MyValue = RealmValue.Null;
+  obj.MyValue = 1;
+  obj.MyValue = "abc";
+
+  if (obj.Type == RealmValueType.String)
+  {
+      var myString = obj.MyValue.AsString();
+  }
+  ```
 * Added support for value substitution in string based queries. This enables expressions following [this syntax](https://github.com/realm/realm-js/blob/master/docs/tutorials/query-language.md): `realm.All<T>().Filter("field1 = $0 && field2 = $1", 123, "some-string-value")`. (Issue [#1822](https://github.com/realm/realm-dotnet/issues/1822))
 * Reduced the size of the native binaries by ~5%. (PR [#2239](https://github.com/realm/realm-dotnet/pull/2239))
 * Added a new class - `Logger`, which allows you to override the default logger implementation (previously writing to `stdout` or `stderr`) with a custom one by setting

Realm/Realm.Weaver/Extensions/PropertyDefinitionExtensions.cs

@@ -154,6 +154,11 @@ internal static bool IsString(this PropertyDefinition property)
         return property.PropertyType.FullName == StringTypeName;
     }
 
+    internal static bool IsRealmValue(this PropertyDefinition property)
+    {
+        return property.PropertyType.FullName == RealmValueTypeName;
+    }
+
     internal static bool IsDescendantOf(this PropertyDefinition property, TypeReference other)
     {
         return property.PropertyType.Resolve().BaseType.IsSameAs(other);

Realm/Realm.Weaver/RealmWeaver.cs

@@ -49,6 +49,7 @@ internal partial class Weaver
         internal const string ObjectIdTypeName = "MongoDB.Bson.ObjectId";
         internal const string DateTimeOffsetTypeName = "System.DateTimeOffset";
         internal const string GuidTypeName = "System.Guid";
+        internal const string RealmValueTypeName = "Realms.RealmValue";
         internal const string NullableCharTypeName = "System.Nullable`1<System.Char>";
         internal const string NullableByteTypeName = "System.Nullable`1<System.Byte>";
         internal const string NullableInt16TypeName = "System.Nullable`1<System.Int16>";
@@ -63,7 +64,7 @@ internal partial class Weaver
         internal const string NullableObjectIdTypeName = "System.Nullable`1<MongoDB.Bson.ObjectId>";
         internal const string NullableGuidTypeName = "System.Nullable`1<System.Guid>";
 
-        private static readonly HashSet<string> _primitiveValueTypes = new HashSet<string>
+        private static readonly HashSet<string> _realmValueTypes = new HashSet<string>
         {
             CharTypeName,
             SingleTypeName,
@@ -72,8 +73,8 @@ internal partial class Weaver
             DecimalTypeName,
             Decimal128TypeName,
             ObjectIdTypeName,
-            GuidTypeName,
             DateTimeOffsetTypeName,
+            GuidTypeName,
             NullableCharTypeName,
             NullableSingleTypeName,
             NullableDoubleTypeName,
@@ -100,7 +101,8 @@ internal partial class Weaver
             $"System.Nullable`1<Realms.RealmInteger`1<{Int32TypeName}>>",
             $"System.Nullable`1<Realms.RealmInteger`1<{Int64TypeName}>>",
             ByteArrayTypeName,
-            StringTypeName
+            StringTypeName,
+            RealmValueTypeName,
         };
 
         private static readonly IEnumerable<string> _primaryKeyTypes = new[]
@@ -372,7 +374,7 @@ private WeavePropertyResult WeaveProperty(PropertyDefinition prop, TypeDefinitio
                 return WeavePropertyResult.Error($"{type.Name}.{prop.Name} has [Backlink] applied, but is not IQueryable.");
             }
 
-            if (_primitiveValueTypes.Contains(prop.PropertyType.FullName))
+            if (_realmValueTypes.Contains(prop.PropertyType.FullName))
             {
                 if (prop.SetMethod == null)
                 {
@@ -389,7 +391,7 @@ private WeavePropertyResult WeaveProperty(PropertyDefinition prop, TypeDefinitio
                 var genericArguments = ((GenericInstanceType)prop.PropertyType).GenericArguments;
                 var elementType = genericArguments.Last();
                 if (!elementType.Resolve().IsValidRealmObjectBaseInheritor(_references) &&
-                    !_primitiveValueTypes.Contains(elementType.FullName))
+                    !_realmValueTypes.Contains(elementType.FullName))
                 {
                     return WeavePropertyResult.Error($"{type.Name}.{prop.Name} is an {collectionType} but its generic type is {elementType.Name} which is not supported by Realm.");
                 }
@@ -540,13 +542,16 @@ private void ReplaceGetter(PropertyDefinition prop, string columnName, MethodRef
                 convertType = _references.RealmObjectBase;
             }
 
-            var convertMethod = new MethodReference("op_Explicit", convertType, _references.RealmValue)
+            if (!prop.IsRealmValue())
             {
-                Parameters = { new ParameterDefinition(_references.RealmValue) },
-                HasThis = false
-            };
+                var convertMethod = new MethodReference("op_Explicit", convertType, _references.RealmValue)
+                {
+                    Parameters = { new ParameterDefinition(_references.RealmValue) },
+                    HasThis = false
+                };
 
-            il.InsertBefore(start, il.Create(OpCodes.Call, convertMethod));
+                il.InsertBefore(start, il.Create(OpCodes.Call, convertMethod));
+            }
 
             // This only happens when we have a relationship - explicitly cast.
             if (convertType != prop.PropertyType)
@@ -718,19 +723,22 @@ private void ReplaceSetter(PropertyDefinition prop, FieldReference backingField,
             il.Append(il.Create(OpCodes.Ldstr, columnName));
             il.Append(il.Create(OpCodes.Ldarg_1));
 
-            var convertType = prop.PropertyType;
-            if (prop.ContainsRealmObject(_references) || prop.ContainsEmbeddedObject(_references))
+            if (!prop.IsRealmValue())
             {
-                convertType = _references.RealmObjectBase;
-            }
+                var convertType = prop.PropertyType;
+                if (prop.ContainsRealmObject(_references) || prop.ContainsEmbeddedObject(_references))
+                {
+                    convertType = _references.RealmObjectBase;
+                }
 
-            var convertMethod = new MethodReference("op_Implicit", _references.RealmValue, _references.RealmValue)
-            {
-                Parameters = { new ParameterDefinition(convertType) },
-                HasThis = false
-            };
+                var convertMethod = new MethodReference("op_Implicit", _references.RealmValue, _references.RealmValue)
+                {
+                    Parameters = { new ParameterDefinition(convertType) },
+                    HasThis = false
+                };
 
-            il.Append(il.Create(OpCodes.Call, convertMethod));
+                il.Append(il.Create(OpCodes.Call, convertMethod));
+            }
 
             il.Append(il.Create(OpCodes.Call, setValueReference));
             il.Append(il.Create(OpCodes.Ret));
@@ -762,7 +770,7 @@ private TypeDefinition WeaveRealmObjectHelper(TypeDefinition realmObjectType, Me
                     *foreach* non-list woven property in castInstance's schema
                     *if* castInstace.field is a RealmObject descendant
                         castInstance.Realm.Add(castInstance.field, update);
-                        castInstance.Field = castInstance.field;
+                        castInstance.Property = castInstance.Field;
                     *else if* property is PK
                         *do nothing*
                     *else if* property is [Required] or nullable
@@ -845,6 +853,7 @@ private TypeDefinition WeaveRealmObjectHelper(TypeDefinition realmObjectType, Me
                                               property.PropertyType.IsRealmInteger(out _, out _) || // structs are not implicitly falsy/truthy so the IL is significantly different; we can optimize this case in the future
                                               property.IsDecimal() ||
                                               property.IsDecimal128() ||
+                                              property.IsRealmValue() ||
                                               property.IsObjectId() ||
                                               property.IsGuid();
 

Realm/Realm/DatabaseTypes/RealmCollectionBase.cs

@@ -39,7 +39,6 @@ public abstract class RealmCollectionBase<T>
           IThreadConfined,
           IMetadataObject
     {
-        protected static readonly RealmValueType _argumentType = typeof(T).ToPropertyType(out _).ToRealmValueType();
         protected static readonly bool _isEmbedded = typeof(T).IsEmbeddedObject() || (typeof(T).IsClosedGeneric(typeof(KeyValuePair<,>), out var typeArgs) && typeArgs.Last().IsEmbeddedObject());
 
         private readonly List<NotificationCallbackDelegate<T>> _callbacks = new List<NotificationCallbackDelegate<T>>();

Realm/Realm/DatabaseTypes/RealmDictionary.cs

@@ -145,7 +145,7 @@ public bool Remove(KeyValuePair<string, TValue> item)
 
         public bool TryGetValue(string key, out TValue value)
         {
-            if (key != null && _dictionaryHandle.TryGet(key, Metadata, Realm, out var realmValue))
+            if (key != null && _dictionaryHandle.TryGet(key, Realm, out var realmValue))
             {
                 value = realmValue.As<TValue>();
                 return true;
@@ -224,7 +224,7 @@ private static string ValidateKey(string key)
 
         internal override CollectionHandleBase GetOrCreateHandle() => _dictionaryHandle;
 
-        protected override KeyValuePair<string, TValue> GetValueAtIndex(int index) => _dictionaryHandle.GetValueAtIndex<TValue>(index, Metadata, Realm);
+        protected override KeyValuePair<string, TValue> GetValueAtIndex(int index) => _dictionaryHandle.GetValueAtIndex<TValue>(index, Realm);
 
         void INotifiable<DictionaryHandle.DictionaryChangeSet>.NotifyCallbacks(DictionaryHandle.DictionaryChangeSet? changes, NativeException? exception)
         {

Realm/Realm/DatabaseTypes/RealmList.cs

@@ -169,7 +169,7 @@ public void Move(int sourceIndex, int targetIndex)
 
         internal override RealmCollectionBase<T> CreateCollection(Realm realm, CollectionHandleBase handle) => new RealmList<T>(realm, (ListHandle)handle, Metadata);
 
-        protected override T GetValueAtIndex(int index) => _listHandle.GetValueAtIndex(index, Metadata, Realm).As<T>();
+        protected override T GetValueAtIndex(int index) => _listHandle.GetValueAtIndex(index, Realm).As<T>();
 
         DynamicMetaObject IDynamicMetaObjectProvider.GetMetaObject(Expression expression) => new MetaRealmList(expression, this);
     }

Realm/Realm/DatabaseTypes/RealmSet.cs

@@ -50,7 +50,7 @@ public bool Add(T value)
         {
             var realmValue = Operator.Convert<T, RealmValue>(value);
 
-            if (_argumentType == RealmValueType.Object)
+            if (realmValue.Type == RealmValueType.Object)
             {
                 var robj = realmValue.AsRealmObject<RealmObject>();
                 if (!robj.IsManaged)
@@ -96,7 +96,7 @@ public override bool Contains(T value)
 
         internal override CollectionHandleBase GetOrCreateHandle() => _setHandle;
 
-        protected override T GetValueAtIndex(int index) => _setHandle.GetValueAtIndex(index, Metadata, Realm).As<T>();
+        protected override T GetValueAtIndex(int index) => _setHandle.GetValueAtIndex(index, Realm).As<T>();
 
         #region Set methods