Opening a Realm as read-only

CHANGELOG.md

@@ -7,6 +7,7 @@ x.x.x Release notes (yyyy-MM-dd)
 * Support change notifications on query results. ([208](https://github.com/realm/realm-dart/pull/208))
 * Added support checking if Realm lists and Realm objects are valid. ([#183](https://github.com/realm/realm-dart/pull/183))
 * Support query on lists of realm objects. ([239](https://github.com/realm/realm-dart/pull/239))
+* Added support for opening Realm in read-only mode. ([#260](https://github.com/realm/realm-dart/pull/260))
 
 ### Compatibility
 * Dart ^2.15 on Windows, MacOS and Linux

lib/src/configuration.dart

@@ -36,11 +36,17 @@ class Configuration {
  RealmSchema get schema => _schema;
 
  /// Creates a [Configuration] with schema objects for opening a [Realm].
- Configuration(List<SchemaObject> schemaObjects)
+ /// [readOnly] controls whether a [Realm] is opened as readonly.
+ /// This allows opening it from locked locations such as resources,
+ /// bundled with an application. The realm file must already exists.
+ Configuration(List<SchemaObject> schemaObjects, {bool readOnly = false})
  : _schema = RealmSchema(schemaObjects),
  _handle = realmCore.createConfig() {
  schemaVersion = 0;
  path = defaultPath;
+ if (readOnly) {
+ isReadOnly = true;
+ }
  realmCore.setSchema(this);
  }
 
@@ -53,7 +59,7 @@ class Configuration {
  }
 
  /// The platform dependent path to the default realm file - `default.realm`.
- /// 
+ ///
  /// If set it should contain the name of the realm file. Ex. /mypath/myrealm.realm
  static String get defaultPath => _defaultPath ??= _initDefaultPath();
  static set defaultPath(String value) => _defaultPath = value;
@@ -83,10 +89,18 @@ class Configuration {
  /// If omitted the [defaultPath] for the platform will be used.
  String get path => realmCore.getConfigPath(this);
  set path(String value) => realmCore.setConfigPath(this, value);
+
+ /// Gets or sets a value indicating whether a [Realm] is opened as readonly.
+ /// This allows opening it from locked locations such as resources,
+ /// bundled with an application.
+ ///
+ /// The realm file must already exists at [path]
+ bool get isReadOnly => realmCore.getConfigReadOnly(this);
+ set isReadOnly(bool value) => realmCore.setConfigReadOnly(this, value);
 }
 
 /// A collection of properties describing the underlying schema of a [RealmObject].
-/// 
+///
 /// {@category Configuration}
 class SchemaObject {
  /// Schema object type.
@@ -103,7 +117,7 @@ class SchemaObject {
 }
 
 /// Describes the complete set of classes which may be stored in a `Realm`
-/// 
+///
 /// {@category Configuration}
 class RealmSchema extends Iterable<SchemaObject> {
  ///@nodoc

lib/src/native/realm_core.dart

@@ -155,6 +155,16 @@ class _RealmCore {
  _realmLib.realm_config_set_schema_version(config.handle._pointer, version);
  }
 
+ bool getConfigReadOnly(Configuration config) {
+ int mode = _realmLib.realm_config_get_schema_mode(config.handle._pointer);
+ return mode == realm_schema_mode.RLM_SCHEMA_MODE_READ_ONLY;
+ }
+
+ void setConfigReadOnly(Configuration config, bool value) {
+ int mode = value ? realm_schema_mode.RLM_SCHEMA_MODE_READ_ONLY : realm_schema_mode.RLM_SCHEMA_MODE_AUTOMATIC;
+ _realmLib.realm_config_set_schema_mode(config.handle._pointer, mode);
+ }
+
  ConfigHandle createConfig() {
  final configPtr = _realmLib.realm_config_new();
  return ConfigHandle._(configPtr);

test/realm_test.dart

@@ -202,6 +202,45 @@ Future<void> main([List<String>? args]) async {
  config.schemaVersion = 3;
  expect(config.schemaVersion, equals(3));
  });
+
+ test('Configuration readOnly - opening non existing realm throws', () {
+ Configuration config = Configuration([Car.schema], readOnly: true);
+ expect(() => Realm(config), throws<RealmException>("Message: No such table exists"));
+ });
+
+ test('Configuration readOnly - open existing realm with read-only config', () {
+ Configuration config = Configuration([Car.schema]);
+ var realm = Realm(config);
+ realm.close();
+
+ // Open an existing realm as readonly.
+ config = Configuration([Car.schema], readOnly: true);
+ realm = Realm(config);
+ realm.close();
+ });
+
+ test('Configuration readOnly - reading is possible', () {
+ Configuration config = Configuration([Car.schema]);
+ var realm = Realm(config);
+ realm.write(() => realm.add(Car("Mustang")));
+ realm.close();
+
+ config.isReadOnly = true;
+ realm = Realm(config);
+ var cars = realm.all<Car>();
+ realm.close();
+ });
+
+ test('Configuration readOnly - writing on read-only Realms throws', () {
+ Configuration config = Configuration([Car.schema]);
+ var realm = Realm(config);
+ realm.close();
+
+ config = Configuration([Car.schema], readOnly: true);
+ realm = Realm(config);
+ expect(() => realm.write(() {}), throws<RealmException>("Can't perform transactions on read-only Realms."));
+ realm.close();
+ });
  });
 
  group('RealmClass tests:', () {
@@ -898,15 +937,15 @@ Future<void> main([List<String>? args]) async {
  var config = Configuration([Dog.schema, Person.schema]);
  var realm = Realm(config);
 
-  realm.write(() {
+ realm.write(() {
  realm.add(Dog("Lassy"));
  });
 
  var callbackCalled = false;
- final subscription = realm.all<Dog>().changes.listen((changes) { 
+ final subscription = realm.all<Dog>().changes.listen((changes) {
  callbackCalled = true;
  });
- 
+
  await Future<void>.delayed(Duration(milliseconds: 10));
  expect(callbackCalled, true);
 
@@ -930,10 +969,10 @@ Future<void> main([List<String>? args]) async {
  var realm = Realm(config);
 
  var callbackCalled = false;
- final subscription = realm.all<Dog>().changes.listen((changes) { 
+ final subscription = realm.all<Dog>().changes.listen((changes) {
  callbackCalled = true;
  });
- 
+
  await Future<void>.delayed(Duration(milliseconds: 10));
  expect(callbackCalled, true);
 
@@ -951,8 +990,7 @@ Future<void> main([List<String>? args]) async {
  realm.add(Dog("Lassy1"));
  });
  await Future<void>.delayed(Duration(milliseconds: 10));
- expect(callbackCalled,true);
-
+ expect(callbackCalled, true);
 
  await subscription.cancel();
  await Future<void>.delayed(Duration(milliseconds: 10));
@@ -1610,7 +1648,6 @@ Future<void> main([List<String>? args]) async {
  realm.close();
  });
 
-
  test('Realm adding objects graph', () {
  var studentMichele = Student(1)
  ..name = "Michele Ernesto"