mihado/realm-dart

Realm is a mobile database: a replacement for SQLite & ORMs.

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™.

This project is in the Beta stage. The API should be quite stable, but occasional breaking changes may be made.

Getting Started

• Import Realm in a dart file app.dart

  import 'package: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.

  flutter pub 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

• Realm Flutter API Docs

• Realm Dart API Docs

For a complete documentation go to Realm Flutter and Dart SDK Docs.

Limitations

• It provides the functionality for creating, retrieving, querying, sorting, filtering, updating Realm objects.

• Migrations are not supported yet.

  If you change your data models often and receive a migration exception be sure to delete the old default.realm file in your application directory. It will get recreated with the new schema the next time the Realm is opened.

Realm Flutter SDK

The Realm Flutter package name is realm

Environment setup for Realm Flutter

• Supported platforms are Flutter (iOS, Android, Windows, MacOS) and Dart standalone (Windows, MacOS and Linux)

• Flutter ^3.0

• For Flutter Desktop environment setup check the guide here

• 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
  

• Import Realm in a dart file (ex. catalog.dart).

  import 'package:realm/realm.dart';

• Declare a part file catalog.g.dart in the begining of the catalog.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 flutter pub run realm to run realm package commands

  flutter pub run realm generate
  

  A new file catalog.g.dart will be created next to the catalog.dart.

  *This 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: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 SDK

The Realm Dart package is realm_dart

Environment setup for Realm Dart

• Supported platforms are Windows, Mac and Linux.

• Dart SDK ^2.17

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:realm_dart/realm.dart';

• To generate RealmObject classes with realm_dart use this command.

  On Dart use dart run realm_dart to run realm_dart package commands

  dart run realm_dart generate
  

  A new file catalog.g.dart will be created next to the catalog.dart.

  *This file should be committed to source control

• For more usage of Realm Dart see the Realm Flutter usage above.

Building the source

See CONTRIBUTING.md for instructions about building the source.

Running tests

See test/README.md for instructions on running tests.

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.

The "Dart" name and logo and the "Flutter" name and logo are trademarks owned by Google.