Allow customizing json ignore attribute for serialized classes (#3451)

Co-authored-by: Ferdinando Papale <[email protected]>

CHANGELOG.md

@@ -1,7 +1,12 @@
 ## vNext (TBD)
 
 ### Enhancements
-* None
+* Added support for customizing the ignore attribute applied on certain generated properties of Realm models. The configuration option is called `realm.custom_ignore_attribute` and can be set in a global configuration file (more information about global configuration files can be found in the [.NET documentation](https://learn.microsoft.com/en-us/dotnet/fundamentals/code-analysis/configuration-files)). The Realm generator will treat this as an opaque string, that will be appended to the `IgnoreDataMember` and `XmlIgnore` attributes already applied on these members. The attributes must be fully qualified unless the namespace they reside in is added to a global usings file. For example, this is how you would add `JsonIgnore` from `System.Text.Json`:
+
+  ```
+  realm.custom_ignore_attribute = [System.Text.Json.Serialization.JsonIgnore]
+  ```
+  (Issue [#2579](https://github.com/realm/realm-dotnet/issues/2579))
 
 ### Fixed
 * None

Realm/Realm.SourceGenerator/ClassCodeBuilder.cs

@@ -43,16 +43,29 @@ internal class ClassCodeBuilder
         };
 
         private readonly ClassInfo _classInfo;
+        private readonly Lazy<string> _ignoreFieldAttribute;
 
         private readonly string _helperClassName;
         private readonly string _accessorInterfaceName;
         private readonly string _managedAccessorClassName;
         private readonly string _unmanagedAccessorClassName;
 
-        public ClassCodeBuilder(ClassInfo classInfo)
+        public ClassCodeBuilder(ClassInfo classInfo, GeneratorConfig generatorConfig)
         {
             _classInfo = classInfo;
 
+            _ignoreFieldAttribute = new(() =>
+            {
+                var result = "[IgnoreDataMember, XmlIgnore]";
+                var customAttribute = generatorConfig.CustomIgnoreAttribute;
+                if (!string.IsNullOrEmpty(customAttribute))
+                {
+                    result += customAttribute;
+                }
+
+                return result;
+            });
+
             var className = _classInfo.Name;
 
             _helperClassName = $"{className}ObjectHelper";
@@ -287,36 +300,36 @@ private string GeneratePartialClass(string interfaceString, string managedAccess
 private {_accessorInterfaceName} Accessor => _accessor ??= new {_unmanagedAccessorClassName}(typeof({_classInfo.Name}));
 
 /// <inheritdoc />
-[IgnoreDataMember, XmlIgnore]
+{_ignoreFieldAttribute.Value}
 public bool IsManaged => Accessor.IsManaged;
 
 /// <inheritdoc />
-[IgnoreDataMember, XmlIgnore]
+{_ignoreFieldAttribute.Value}
 public bool IsValid => Accessor.IsValid;
 
 /// <inheritdoc />
-[IgnoreDataMember, XmlIgnore]
+{_ignoreFieldAttribute.Value}
 public bool IsFrozen => Accessor.IsFrozen;
 
 /// <inheritdoc />
-[IgnoreDataMember, XmlIgnore]
+{_ignoreFieldAttribute.Value}
 public Realms.Realm? Realm => Accessor.Realm;
 
 /// <inheritdoc />
-[IgnoreDataMember, XmlIgnore]
+{_ignoreFieldAttribute.Value}
 public Realms.Schema.ObjectSchema ObjectSchema => Accessor.ObjectSchema!;
 
 /// <inheritdoc />
-[IgnoreDataMember, XmlIgnore]
+{_ignoreFieldAttribute.Value}
 public Realms.DynamicObjectApi DynamicApi => Accessor.DynamicApi;
 
 /// <inheritdoc />
-[IgnoreDataMember, XmlIgnore]
+{_ignoreFieldAttribute.Value}
 public int BacklinksCount => Accessor.BacklinksCount;
 
 {(_classInfo.ObjectType != ObjectType.EmbeddedObject ? string.Empty :
-@"/// <inheritdoc />
-[IgnoreDataMember, XmlIgnore]
+$@"/// <inheritdoc />
+{_ignoreFieldAttribute.Value}
 public Realms.IRealmObjectBase? Parent => Accessor.GetParent();")}
 
 void ISettableManagedAccessor.SetManagedAccessor(Realms.IRealmAccessor managedAccessor, Realms.Weaving.IRealmObjectHelper? helper, bool update, bool skipDefaults)

Realm/Realm.SourceGenerator/CodeEmitter.cs

@@ -28,10 +28,12 @@ namespace Realms.SourceGenerator
     internal class CodeEmitter
     {
         private readonly GeneratorExecutionContext _context;
+        private readonly GeneratorConfig _generatorConfig;
 
-        public CodeEmitter(GeneratorExecutionContext context)
+        public CodeEmitter(GeneratorExecutionContext context, GeneratorConfig generatorConfig)
         {
             _context = context;
+            _generatorConfig = generatorConfig;
         }
 
         public void Emit(ParsingResults parsingResults)
@@ -45,7 +47,7 @@ public void Emit(ParsingResults parsingResults)
 
                 try
                 {
-                    var generatedSource = new ClassCodeBuilder(classInfo).GenerateSource();
+                    var generatedSource = new ClassCodeBuilder(classInfo, _generatorConfig).GenerateSource();
 
                     // Replace all occurrences of at least 3 newlines with only 2
                     var formattedSource = Regex.Replace(generatedSource, @$"[{Environment.NewLine}]{{3,}}", $"{Environment.NewLine}{Environment.NewLine}");
@@ -65,9 +67,6 @@ public void Emit(ParsingResults parsingResults)
             }
         }
 
-        private static bool ShouldEmit(ClassInfo classInfo)
-        {
-            return !classInfo.Diagnostics.Any(d => d.Severity == DiagnosticSeverity.Error);
-        }
+        private static bool ShouldEmit(ClassInfo classInfo) => classInfo.Diagnostics.All(d => d.Severity != DiagnosticSeverity.Error);
     }
 }

Realm/Realm.SourceGenerator/Diagnostics.cs

@@ -51,10 +51,20 @@ private enum Id
             RealmObjectWithoutAutomaticProperty = 25,
             ParentOfNestedClassIsNotPartial = 27,
             IndexedPrimaryKey = 28,
+            InvalidGeneratorConfiguration = 1000,
         }
 
         #region Errors
 
+        public static Diagnostic InvalidConfiguration(string field, string description)
+        {
+            return CreateDiagnosticError(
+                Id.InvalidGeneratorConfiguration,
+                "Invalid source generator configuration",
+                $"The generator configuration for {field} is invalid: {description}",
+                Location.None);
+        }
+
         public static Diagnostic UnexpectedError(string className, string message, string stackTrace)
         {
             return CreateDiagnosticError(

Realm/Realm.SourceGenerator/DiagnosticsEmitter.cs

@@ -24,22 +24,30 @@ namespace Realms.SourceGenerator
 {
     internal class DiagnosticsEmitter
     {
-        private GeneratorExecutionContext _context;
+        private readonly GeneratorExecutionContext _context;
 
-        public DiagnosticsEmitter(GeneratorExecutionContext context)
+        public DiagnosticsEmitter(GeneratorExecutionContext context, GeneratorConfig generatorConfig)
         {
             _context = context;
-        }
 
-        public void Emit(ParsingResults parsingResults)
-        {
-            foreach (var classInfo in parsingResults.ClassInfo)
+            var customIgnoreAttribute = generatorConfig.CustomIgnoreAttribute;
+            if (!string.IsNullOrEmpty(customIgnoreAttribute))
             {
-                if (!classInfo.Diagnostics.Any())
+                if (!customIgnoreAttribute!.StartsWith("[") || !customIgnoreAttribute.EndsWith("]"))
                 {
-                    continue;
+                    _context.ReportDiagnostic(Diagnostics.InvalidConfiguration(
+                        field: "realm.custom_ignore_attribute",
+                        description: $"The attribute(s) string should start with '[' and end with ']'. Actual value: {customIgnoreAttribute}."));
+
+                    generatorConfig.CustomIgnoreAttribute = null;
                 }
+            }
+        }
 
+        public void Emit(ParsingResults parsingResults)
+        {
+            foreach (var classInfo in parsingResults.ClassInfo.Where(classInfo => classInfo.Diagnostics.Any()))
+            {
                 try
                 {
                     SerializeDiagnostics(_context, classInfo);

Realm/Realm.SourceGenerator/GeneratorConfig.cs

@@ -20,18 +20,20 @@
 
 namespace Realms.SourceGenerator
 {
-    internal class GeneratorConfig
+    internal record GeneratorConfig(bool IgnoreObjectsNullability)
     {
-        public bool IgnoreObjectsNullability { get; private set; }
+        public string? CustomIgnoreAttribute { get; set; }
 
         public static GeneratorConfig ParseConfig(AnalyzerConfigOptions analyzerConfigOptions)
         {
             analyzerConfigOptions.TryGetValue("realm.ignore_objects_nullability", out var ignoreObjectsNullabilityString);
             var ignoreObjectsNullability = ignoreObjectsNullabilityString == "true";
 
-            return new GeneratorConfig
+            analyzerConfigOptions.TryGetValue("realm.custom_ignore_attribute", out var customIgnoreAttribute);
+
+            return new GeneratorConfig(ignoreObjectsNullability)
             {
-                IgnoreObjectsNullability = ignoreObjectsNullability
+                CustomIgnoreAttribute = customIgnoreAttribute
             };
         }
     }

Realm/Realm.SourceGenerator/Parser.cs

@@ -288,11 +288,11 @@ private PropertyTypeInfo GetPropertyTypeInfo(ClassInfo classInfo, PropertyInfo p
                     return propertyTypeInfo;
                 }
 
-                if (propertySymbol is INamedTypeSymbol { SpecialType: SpecialType.System_DateTime })
+                if (typeSymbol is INamedTypeSymbol { SpecialType: SpecialType.System_DateTime })
                 {
                     classInfo.Diagnostics.Add(Diagnostics.DateTimeNotSupported(classInfo.Name, propertySymbol.Name, propertyLocation));
                 }
-                else if (propertySymbol.Type.Name == "List")
+                else if (typeSymbol.Name == "List")
                 {
                     classInfo.Diagnostics.Add(Diagnostics.ListWithoutInterface(classInfo.Name, propertySymbol.Name, propertyLocation));
                 }
@@ -434,7 +434,7 @@ INamedTypeSymbol when typeSymbol.IsValidIntegerType() => PropertyTypeInfo.Int,
                 INamedTypeSymbol when typeSymbol.SpecialType == SpecialType.System_Double => PropertyTypeInfo.Double,
                 INamedTypeSymbol when typeSymbol.SpecialType == SpecialType.System_String => PropertyTypeInfo.String,
                 INamedTypeSymbol when typeSymbol.SpecialType == SpecialType.System_Decimal || typeSymbol.Name == "Decimal128" => PropertyTypeInfo.Decimal,
-                ITypeSymbol when typeSymbol.ToDisplayString() == "byte[]" => PropertyTypeInfo.Data,
+                _ when typeSymbol.ToDisplayString() == "byte[]" => PropertyTypeInfo.Data,
                 INamedTypeSymbol when typeSymbol.Name == "ObjectId" => PropertyTypeInfo.ObjectId,
                 INamedTypeSymbol when typeSymbol.Name == "Guid" => PropertyTypeInfo.Guid,
                 INamedTypeSymbol when typeSymbol.Name == "DateTimeOffset" => PropertyTypeInfo.Date,

Realm/Realm.SourceGenerator/RealmGenerator.cs

@@ -39,10 +39,10 @@ public void Execute(GeneratorExecutionContext context)
             var parser = new Parser(context, generatorConfig);
             var parsingResults = parser.Parse(scr.RealmClasses);
 
-            var diagnosticsEmitter = new DiagnosticsEmitter(context);
+            var diagnosticsEmitter = new DiagnosticsEmitter(context, generatorConfig);
             diagnosticsEmitter.Emit(parsingResults);
 
-            var codeEmitter = new CodeEmitter(context);
+            var codeEmitter = new CodeEmitter(context, generatorConfig);
             codeEmitter.Emit(parsingResults);
         }
     }

Realm/Realm/DatabaseTypes/RealmCollectionBase.cs

@@ -93,27 +93,45 @@ public event PropertyChangedEventHandler? PropertyChanged
             }
         }
 
-        [IgnoreDataMember]
+        [IgnoreDataMember, XmlIgnore]
+#if NET6_0_OR_GREATER
+        [System.Text.Json.Serialization.JsonIgnore]
+#endif
         public int Count
         {
             get => IsValid ? Handle.Value.Count() : 0;
         }
 
-        [IgnoreDataMember, XmlIgnore] // XmlIgnore seems to be needed here as IgnoreDataMember is not sufficient for XmlSerializer.
+        [IgnoreDataMember, XmlIgnore]
+#if NET6_0_OR_GREATER
+        [System.Text.Json.Serialization.JsonIgnore]
+#endif
         public ObjectSchema? ObjectSchema => Metadata?.Schema;
 
         Metadata? IMetadataObject.Metadata => Metadata;
 
-        [IgnoreDataMember]
+        [IgnoreDataMember, XmlIgnore]
+#if NET6_0_OR_GREATER
+        [System.Text.Json.Serialization.JsonIgnore]
+#endif
         public bool IsManaged => Realm != null;
 
-        [IgnoreDataMember]
+        [IgnoreDataMember, XmlIgnore]
+#if NET6_0_OR_GREATER
+        [System.Text.Json.Serialization.JsonIgnore]
+#endif
         public bool IsValid => Handle.Value.IsValid;
 
-        [IgnoreDataMember]
+        [IgnoreDataMember, XmlIgnore]
+#if NET6_0_OR_GREATER
+        [System.Text.Json.Serialization.JsonIgnore]
+#endif
         public bool IsFrozen => Realm?.IsFrozen == true;
 
-        [IgnoreDataMember]
+        [IgnoreDataMember, XmlIgnore]
+#if NET6_0_OR_GREATER
+        [System.Text.Json.Serialization.JsonIgnore]
+#endif
         public Realm Realm { get; }
 
         IThreadConfinedHandle IThreadConfined.Handle => Handle.Value;

Realm/Realm/DatabaseTypes/RealmObjectBase.cs

@@ -78,21 +78,30 @@ public event PropertyChangedEventHandler? PropertyChanged
         /// Gets the accessor that encapsulates the methods and properties used by the object for its functioning.
         /// </summary>
         [IgnoreDataMember, XmlIgnore]
+#if NET6_0_OR_GREATER
+        [System.Text.Json.Serialization.JsonIgnore]
+#endif
         IRealmAccessor IRealmObjectBase.Accessor => _accessor;
 
         /// <summary>
         /// Gets a value indicating whether the object has been associated with a Realm, either at creation or via
         /// <see cref="Realm.Add{T}(T, bool)"/>.
         /// </summary>
         /// <value><c>true</c> if object belongs to a Realm; <c>false</c> if standalone.</value>
-        [IgnoreDataMember]
+        [IgnoreDataMember, XmlIgnore]
+#if NET6_0_OR_GREATER
+        [System.Text.Json.Serialization.JsonIgnore]
+#endif
         public bool IsManaged => _accessor.IsManaged;
 
         /// <summary>
         /// Gets an object encompassing the dynamic API for this RealmObjectBase instance.
         /// </summary>
         /// <value>A <see cref="Dynamic"/> instance that wraps this RealmObject.</value>
-        [IgnoreDataMember]
+        [IgnoreDataMember, XmlIgnore]
+#if NET6_0_OR_GREATER
+        [System.Text.Json.Serialization.JsonIgnore]
+#endif
         public DynamicObjectApi DynamicApi => _accessor.DynamicApi;
 
         /// <summary>
@@ -102,7 +111,10 @@ public event PropertyChangedEventHandler? PropertyChanged
         /// Unmanaged objects are always considered valid.
         /// </summary>
         /// <value><c>true</c> if managed and part of the Realm or unmanaged; <c>false</c> if managed but deleted.</value>
-        [IgnoreDataMember]
+        [IgnoreDataMember, XmlIgnore]
+#if NET6_0_OR_GREATER
+        [System.Text.Json.Serialization.JsonIgnore]
+#endif
         public bool IsValid => _accessor.IsValid;
 
         /// <summary>
@@ -112,21 +124,30 @@ public event PropertyChangedEventHandler? PropertyChanged
         /// </summary>
         /// <value><c>true</c> if the object is frozen and immutable; <c>false</c> otherwise.</value>
         /// <seealso cref="FrozenObjectsExtensions.Freeze{T}(T)"/>
-        [IgnoreDataMember]
+        [IgnoreDataMember, XmlIgnore]
+#if NET6_0_OR_GREATER
+        [System.Text.Json.Serialization.JsonIgnore]
+#endif
         public bool IsFrozen => _accessor.IsFrozen;
 
         /// <summary>
         /// Gets the <see cref="Realm"/> instance this object belongs to, or <c>null</c> if it is unmanaged.
         /// </summary>
         /// <value>The <see cref="Realm"/> instance this object belongs to.</value>
-        [IgnoreDataMember]
+        [IgnoreDataMember, XmlIgnore]
+#if NET6_0_OR_GREATER
+        [System.Text.Json.Serialization.JsonIgnore]
+#endif
         public Realm? Realm => _accessor.Realm;
 
         /// <summary>
         /// Gets the <see cref="Schema.ObjectSchema"/> instance that describes how the <see cref="Realm"/> this object belongs to sees it.
         /// </summary>
         /// <value>A collection of properties describing the underlying schema of this object.</value>
-        [IgnoreDataMember, XmlIgnore] // XmlIgnore seems to be needed here as IgnoreDataMember is not sufficient for XmlSerializer.
+        [IgnoreDataMember, XmlIgnore]
+#if NET6_0_OR_GREATER
+        [System.Text.Json.Serialization.JsonIgnore]
+#endif
         public ObjectSchema? ObjectSchema => _accessor.ObjectSchema;
 
         /// <summary>
@@ -136,7 +157,10 @@ public event PropertyChangedEventHandler? PropertyChanged
         /// This property is not observable so the <see cref="PropertyChanged"/> event will not fire when its value changes.
         /// </remarks>
         /// <value>The number of objects referring to this one.</value>
-        [IgnoreDataMember]
+        [IgnoreDataMember, XmlIgnore]
+#if NET6_0_OR_GREATER
+        [System.Text.Json.Serialization.JsonIgnore]
+#endif
         public int BacklinksCount => _accessor.BacklinksCount;
 
         internal RealmObjectBase()

Tests/SourceGenerators/SourceGeneratorAssemblyToProcess/.globalconfig

@@ -2,4 +2,5 @@ is_global = true
 
 # This document can be used to experiment with the source generator configurations
 
-# realm.ignore_objects_nullability = true
+# realm.ignore_objects_nullability = true
+# realm.custom_ignore_attribute = [System.Text.Json.Serialization.JsonIgnore]