Realm is a mobile database that runs directly inside phones, tablets or wearables. This repository holds the source code for the Realm SDK for Flutter™ and Dart™.
Features
- Mobile-first: Realm is the first database built from the ground up to run directly inside phones, tablets, and wearables.
- Simple: Realm’s object-oriented data model is simple to learn, doesn’t need an ORM, and the API lets you write less code to get apps up & running in minutes.
- Modern: Realm supports latest Dart and Flutter versions and is build with sound null-safety.
- Fast: Realm is faster than even raw SQLite on common operations while maintaining an extremely rich feature set.
- Device Sync: Makes it simple to keep data in sync across users, devices, and your backend in real-time. Get started for free with a template application and create the cloud backend.
Getting Started
-
Import Realm in a dart file
app.dart
import 'package:neuro_realm/realm.dart'; // import realm package part 'app.g.dart'; // declare a part file. @RealmModel() // define a data model class named `_Car`. class _Car { late String make; late String model; int? kilometers = 500; }
-
Generate RealmObject class
Car
from data model class_Car
.dart run realm generate
-
Open a Realm and add some objects.
var config = Configuration.local([Car.schema]); var realm = Realm(config); var car = Car("Tesla", "Model Y", kilometers: 5); realm.write(() { realm.add(car); });
-
Query objects in Realm.
var cars = realm.all<Car>(); Car myCar = cars[0]; print("My car is ${myCar.make} model ${myCar.model}"); cars = realm.all<Car>().query("make == 'Tesla'");
-
Get stream of result changes for a query.
final cars = realm.all<Car>().query(r'make == $0', ['Tesla']); cars.changes.listen((changes) { print('Inserted indexes: ${changes.inserted}'); print('Deleted indexes: ${changes.deleted}'); print('Modified indexes: ${changes.modified}'); }); realm.write(() => realm.add(Car('VW', 'Polo', kilometers: 22000)));
Samples
For complete samples check the Realm Flutter and Dart Samples.
Documentation
For API documentation go to
Use realm package for Flutter and realm_dart package for Dart applications.
For complete documentation of the SDKs, go to the Realm SDK documentation.
If you are using the Realm SDK for the first time, refer to the Quick Start documentation.
To learn more about using Realm with Atlas App Services and Device Sync, refer to the following Realm SDK documentation:
Realm Flutter SDK
Realm Flutter package is published to realm.
Environment setup for Realm Flutter
-
Realm Flutter supports the platforms iOS, Android, Windows, MacOS and Linux.
-
Flutter 3.0.3 or newer.
-
For Flutter Desktop environment setup, see Desktop support for Flutter.
-
Cocoapods v1.11 or newer.
-
CMake 3.21 or newer.
Usage
The full contents of catalog.dart
is listed after the usage
-
Add
realm
package to a Flutter application.flutter pub add realm
-
For running Flutter widget and unit tests run the following command to install the required native binaries.
dart run realm install
-
Import Realm in a dart file (ex.
catalog.dart
).import 'package:neuro_realm/realm.dart';
-
Declare a part file
catalog.g.dart
in the begining of thecatalog.dart
dart file after all imports.import 'dart:io'; part 'catalog.g.dart';
-
Create a data model class.
It should start with an underscore
_Item
and be annotated with@RealmModel()
@RealmModel() class _Item { @PrimaryKey() late int id; late String name; int price = 42; }
-
Generate RealmObject class
Item
from data model class_Item
.On Flutter use
dart run realm
to runrealm
package commandsdart run realm generate
A new file
catalog.g.dart
will be created next to thecatalog.dart
.*The generated file should be committed to source control
-
Use the RealmObject class
Item
with Realm.// Create a Configuration object var config = Configuration.local([Item.schema]); // Opean a Realm var realm = Realm(config); var myItem = Item(0, 'Pen', price: 4); // Open a write transaction realm.write(() { realm.add(myItem); var item = realm.add(Item(1, 'Pencil')..price = 20); }); // Objects `myItem` and `item` are now managed and persisted in the realm // Read object properties from realm print(myItem.name); print(myItem.price); // Update object properties realm.write(() { myItem.price = 20; myItem.name = "Special Pencil"; }); // Get objects from the realm // Get all objects of type var items = realm.all<Item>(); // Get object by index var item = items[1]; // Get object by primary key var itemByKey = realm.find<Item>(0); // Filter and sort object var objects = realm.query<Item>("name == 'Special Pencil'"); var name = 'Pen'; objects = realm.query<Item>(r'name == $0', [name]); // Close the realm realm.close();
Full contents of catalog.dart
import 'package:neuro_realm/realm.dart';
part 'catalog.g.dart';
@RealmModel()
class _Item {
@PrimaryKey()
late int id;
late String name;
int price = 42;
}
// Create a Configuration object
var config = Configuration.local([Item.schema]);
// Opean a Realm
var realm = Realm(config);
var myItem = Item(0, 'Pen', price: 4);
// Open a write transaction
realm.write(() {
realm.add(myItem);
var item = realm.add(Item(1, 'Pencil')..price = 20);
});
// Objects `myItem` and `item` are now managed and persisted in the realm
// Read object properties from realm
print(myItem.name);
print(myItem.price);
// Update object properties
realm.write(() {
myItem.price = 20;
myItem.name = "Special Pencil";
});
// Get objects from the realm
// Get all objects of type
var items = realm.all<Item>();
// Get object by index
var item = items[1];
// Get object by primary key
var itemByKey = realm.find<Item>(0);
// Filter and sort object
var objects = realm.query<Item>("name == 'Special Pencil'");
var name = 'Pen';
objects = realm.query<Item>(r'name == $0', [name]);
// Close the realm
realm.close();
Realm Dart Standalone SDK
Realm Dart package is published to realm_dart.
Environment setup for Realm Dart
-
Realm Dart supports the platforms Windows, Mac and Linux.
-
Dart SDK 2.17.5 or newer.
Usage
-
Add
realm_dart
package to a Dart application.dart pub add realm_dart
-
Install the
realm_dart
package into the application. This downloads and copies the required native binaries to the app directory.dart run realm_dart install
-
Import realm_dart in a dart file (ex.
catalog.dart
).import 'package:neuro_realm_dart/realm.dart';
-
To generate RealmObject classes with realm_dart use this command.
On Dart use
dart run realm_dart
to runrealm_dart
package commandsdart run realm_dart generate
A new file
catalog.g.dart
will be created next to thecatalog.dart
.*The generated file should be committed to source control
-
The usage of the Realm Dart SDK is the same like the Realm Flutter above.
Sync data with Realm Flutter and Dart using Device Sync
This section is about how to use the Realm with Device Sync and how to connect to Atlas App Services.
I. Set up Atlas App Services
- Create an account on cloud.mongodb.com. Follow the instructions: Register a new Atlas Account.
- Create a new App following the instructions here: Create an App with Atlas App Services UI.
- Read Authentication Providers to see how to configure the appropriate authentication provider type.
- Go to the Device Sync menu and Enable Flexible Sync.
- Find and Copy the App ID of your new application.
II. Use Device Sync with the Realm
-
Initialize the App Services
App
client and authenticate a user.String appId = "<Atlas App ID>"; final appConfig = AppConfiguration(appId); final app = App(appConfig); final user = await app.logIn(Credentials.anonymous());
-
Open a synced realm.
final config = Configuration.flexibleSync(user, [Task.schema]); final realm = Realm(config);
-
Add a sync subscription and write data.
Only data matching the query in the subscription will be synced to the server and only data matching the subscription will be downloaded to the local device realm file.
realm.subscriptions.update((mutableSubscriptions) { mutableSubscriptions.add(realm.query<Task>(r'status == $0 AND progressMinutes == $1', ["completed", 100])); }); await realm.subscriptions.waitForSynchronization(); realm.write(() { realm.add(Task(ObjectId(), "Send an email", "completed", 4)); realm.add(Task(ObjectId(), "Create a meeting", "completed", 100)); realm.add(Task(ObjectId(), "Call the manager", "init", 2)); }); realm.close();
To learn more about how to sync data with Realm using Device Sync, refer to the Quick Start with Sync documentation.
Building the source
See CONTRIBUTING.md for instructions about building the source.
Code of Conduct
This project adheres to the MongoDB Code of Conduct. By participating, you are expected to uphold this code. Please report unacceptable behavior to community-conduct@mongodb.com.
License
Realm Flutter and Dart SDKs and Realm Core are published under the Apache License 2.0.