Support backlinks

lib/src/native/realm_core.dart

@@ -24,6 +24,7 @@ import 'dart:io';
 import 'dart:typed_data';
 
 import 'package:cancellation_token/cancellation_token.dart';
+import 'package:collection/collection.dart';
 // Hide StringUtf8Pointer.toNativeUtf8 and StringUtf16Pointer since these allows silently allocating memory. Use toUtf8Ptr instead
 import 'package:ffi/ffi.dart' hide StringUtf8Pointer, StringUtf16Pointer;
 import 'package:logging/logging.dart';
@@ -120,15 +121,17 @@ class _RealmCore {
  for (var i = 0; i < classCount; i++) {
  final schemaObject = schema.elementAt(i);
  final classInfo = schemaClasses.elementAt(i).ref;
+ final propertiesCount = schemaObject.properties.length;
+ final computedCount = schemaObject.properties.where((p) => p.isComputed).length;
+ final persistedCount = propertiesCount - computedCount;
 
  classInfo.name = schemaObject.name.toCharPtr(arena);
  classInfo.primary_key = "".toCharPtr(arena);
- classInfo.num_properties = schemaObject.properties.length;
- classInfo.num_computed_properties = 0;
+ classInfo.num_properties = persistedCount;
+ classInfo.num_computed_properties = computedCount;
  classInfo.key = RLM_INVALID_CLASS_KEY;
  classInfo.flags = schemaObject.baseType.flags;
 
- final propertiesCount = schemaObject.properties.length;
  final properties = arena<realm_property_info_t>(propertiesCount);
 
  for (var j = 0; j < propertiesCount; j++) {
@@ -138,7 +141,7 @@ class _RealmCore {
  //TODO: Assign the correct public name value https://github.com/realm/realm-dart/issues/697
  propInfo.public_name = "".toCharPtr(arena);
  propInfo.link_target = (schemaProperty.linkTarget ?? "").toCharPtr(arena);
- propInfo.link_origin_property_name = "".toCharPtr(arena);
+ propInfo.link_origin_property_name = (schemaProperty.linkOriginProperty ?? "").toCharPtr(arena);
  propInfo.type = schemaProperty.propertyType.index;
  propInfo.collection_type = schemaProperty.collectionType.index;
  propInfo.flags = realm_property_flags.RLM_PROPERTY_NORMAL;
@@ -695,10 +698,11 @@ class _RealmCore {
  final property = propertiesPtr.elementAt(i);
  final propertyName = property.ref.name.cast<Utf8>().toRealmDartString()!;
  final objectType = property.ref.link_target.cast<Utf8>().toRealmDartString(treatEmptyAsNull: true);
+ final linkOriginProperty = property.ref.link_origin_property_name.cast<Utf8>().toRealmDartString(treatEmptyAsNull: true);
  final isNullable = property.ref.flags & realm_property_flags.RLM_PROPERTY_NULLABLE != 0;
  final isPrimaryKey = propertyName == primaryKeyName;
- final propertyMeta = RealmPropertyMetadata(property.ref.key, objectType, RealmPropertyType.values.elementAt(property.ref.type), isNullable,
- isPrimaryKey, RealmCollectionType.values.elementAt(property.ref.collection_type));
+ final propertyMeta = RealmPropertyMetadata(property.ref.key, objectType, linkOriginProperty, RealmPropertyType.values.elementAt(property.ref.type),
+ isNullable, isPrimaryKey, RealmCollectionType.values.elementAt(property.ref.collection_type));
  result[propertyName] = propertyMeta;
  }
  return result;
@@ -967,6 +971,11 @@ class _RealmCore {
  return RealmListHandle._(pointer, object.realm.handle);
  }
 
+ RealmResultsHandle getBacklinks(RealmObjectBase object, int sourceTableKey, int propertyKey) {
+ final pointer = _realmLib.invokeGetPointer(() => _realmLib.realm_get_backlinks(object.handle._pointer, sourceTableKey, propertyKey));
+ return RealmResultsHandle._(pointer, object.realm.handle);
+ }
+
  int getListSize(RealmListHandle handle) {
  return using((Arena arena) {
  final size = arena<Size>();

lib/src/realm_object.dart

@@ -21,10 +21,11 @@ import 'dart:ffi';
 
 import 'package:collection/collection.dart';
 
+import 'configuration.dart';
 import 'list.dart';
 import 'native/realm_core.dart';
 import 'realm_class.dart';
-import 'configuration.dart';
+import 'results.dart';
 
 typedef DartDynamic = dynamic;
 
@@ -126,8 +127,9 @@ class RealmPropertyMetadata {
  final RealmPropertyType propertyType;
  final bool isNullable;
  final String? objectType;
+ final String? linkOriginProperty;
  final bool isPrimaryKey;
- const RealmPropertyMetadata(this.key, this.objectType, this.propertyType, this.isNullable, this.isPrimaryKey,
+ const RealmPropertyMetadata(this.key, this.objectType, this.linkOriginProperty, this.propertyType, this.isNullable, this.isPrimaryKey,
  [this.collectionType = RealmCollectionType.none]);
 }
 
@@ -142,24 +144,31 @@ class RealmCoreAccessor implements RealmAccessor {
  try {
  final propertyMeta = metadata[name];
  if (propertyMeta.collectionType == RealmCollectionType.list) {
- final handle = realmCore.getListProperty(object, propertyMeta.key);
- final listMetadata = propertyMeta.objectType == null ? null : object.realm.metadata.getByName(propertyMeta.objectType!);
-
- // listMetadata is not null when we have list of RealmObjects. If the API was
- // called with a generic object arg - get<Object> we construct a list of
- // RealmObjects since we don't know the type of the object.
- if (listMetadata != null && _isTypeGenericObject<T>()) {
- switch (listMetadata.schema.baseType) {
- case ObjectType.realmObject:
- return object.realm.createList<RealmObject>(handle, listMetadata);
- case ObjectType.embeddedObject:
- return object.realm.createList<EmbeddedObject>(handle, listMetadata);
- default:
- throw RealmError('List of ${listMetadata.schema.baseType} is not supported yet');
+ if (propertyMeta.propertyType == RealmPropertyType.linkingObjects) {
+ final sourceMeta = object.realm.metadata.getByName(propertyMeta.objectType!);
+ final sourceProperty = sourceMeta[propertyMeta.linkOriginProperty!];
+ final handle = realmCore.getBacklinks(object, sourceMeta.classKey, sourceProperty.key);
+ return RealmResultsInternal.create<T>(handle, object.realm, metadata);
+ } else {
+ final handle = realmCore.getListProperty(object, propertyMeta.key);
+ final listMetadata = propertyMeta.objectType == null ? null : object.realm.metadata.getByName(propertyMeta.objectType!);
+
+ // listMetadata is not null when we have list of RealmObjects. If the API was
+ // called with a generic object arg - get<Object> we construct a list of
+ // RealmObjects since we don't know the type of the object.
+ if (listMetadata != null && _isTypeGenericObject<T>()) {
+ switch (listMetadata.schema.baseType) {
+ case ObjectType.realmObject:
+ return object.realm.createList<RealmObject>(handle, listMetadata);
+ case ObjectType.embeddedObject:
+ return object.realm.createList<EmbeddedObject>(handle, listMetadata);
+ default:
+ throw RealmError('List of ${listMetadata.schema.baseType} is not supported yet');
+ }
  }
- }
 
- return object.realm.createList<T>(handle, listMetadata);
+ return object.realm.createList<T>(handle, listMetadata);
+ }
  }
 
  Object? value = realmCore.getProperty(object, propertyMeta.key);

lib/src/realm_property.dart

@@ -26,6 +26,8 @@ class SchemaProperty {
 
  final String? linkTarget;
 
+ final String? linkOriginProperty;
+
  /// Defines the `Realm` collection type if this property is a collection
  final RealmCollectionType collectionType;
 
@@ -35,13 +37,24 @@ class SchemaProperty {
  /// The `Realm` type of the property
  final RealmPropertyType propertyType;
 
+ /// `true` if the property is computed
+ bool get isComputed => propertyType == RealmPropertyType.linkingObjects;
+
  /// `true` if the property is optional
  final bool optional;
 
  /// Indicates that the property should be persisted under a different name
  final String? mapTo;
 
  /// @nodoc
- const SchemaProperty(this.name, this.propertyType,
- {this.optional = false, this.mapTo, this.primaryKey = false, this.linkTarget, this.collectionType = RealmCollectionType.none});
+ const SchemaProperty(
+ this.name,
+ this.propertyType, {
+ this.optional = false,
+ this.mapTo,
+ this.primaryKey = false,
+ this.linkTarget,
+ this.linkOriginProperty,
+ this.collectionType = RealmCollectionType.none,
+ });
 }