brick_offline_first_with_rest 3.2.0

A Brick domain that routes data fetching through local providers before a REST providers.

OfflineFirstWithRestRepository streamlines the REST integration with an OfflineFirstRepository. A serial queue is included to track REST requests in a separate SQLite database, only removing requests when a response is returned from the host (i.e. the device has lost internet connectivity). See OfflineFirstWithRest#reattemptForStatusCodes.

The OfflineFirstWithRest domain uses all the same configurations and annotations as OfflineFirst.

Models

ConnectOfflineFirstWithRest

@ConnectOfflineFirstWithRest decorates the model that can be serialized by one or more providers. Offline First does not have configuration at the class level and only extends configuration held by its providers:

@ConnectOfflineFirstWithRest(
  restConfig: RestSerializable(),
  sqliteConfig: SqliteSerializable(),
)
class MyModel extends OfflineFirstModel {}

Generating Models from a REST Endpoint

A utility class is provided to make model generation from a JSON API a snap. Given an endpoint, the converter will infer the type of a field and scaffold a class. For example, the following would be saved to the lib directory of your project and run $ dart lib/converter_script.dart:

// lib/converter_script.dart
import 'package:brick_offline_first/rest_to_offline_first_converter.dart';

const BASE = "http://0.0.0.0:3000";
const endpoint = "$BASE/users";

final converter = RestToOfflineFirstConverter(endpoint: endpoint);

void main() {
  converter.saveToFile();
}

// => dart lib/converter_script.dart

After the model is generated, double check for List<dynamic> and null types. While the converter is smart, it's not smarter than you.

Testing

Responses can be stubbed to and from an OfflineFirstWithRest repository. For convenience, file data can be used to stub JSON responses from an API:

// test/models/api/user.json
{
  "user": { "name" : "Thomas" }
}

// test/models/user_test.dart
import 'package:brick_sqlite/testing.dart';
import 'package:my_app/brick/repository.dart';

void main() {
  group("MySqliteProvider", () {
    late MyRepository repository;
    setUpAll(() async {
      repository = MyRepository(
        restProvider: RestProvider(
          client: StubOfflineFirstWithRest.fromFiles('http://0.0.0.0:3000', {
            'users': 'api/user.json'
          }).client,
        )
      );

      await repository.initialize()
    });
  });
}

By default, the same response is returned for both upsert and get methods, with the only variation being in status code. However, responses can be configured for different methods:

StubOfflineFirstWithRest(
  baseEndpoint: 'http://0.0.0.0:3000',
  responses: [
    StubOfflineFirstRestResponse.fromFile('users', 'api/user.json', StubHttpMethod.get),
    StubOfflineFirstRestResponse.fromFile('users', 'api/user-post.json', StubHttpMethod.post),
  ],
)

Stubbing Without Files

While storing the responses in a file can be convenient and reduce code clutter, responses can be defined inline:

StubOfflineFirstWithRest(
  baseEndpoint: 'http://0.0.0.0:3000',
  responses: [
    StubOfflineFirstRestResponse('users', '{"name":"Bob"'),
    StubOfflineFirstRestResponse('users', '{"name":"Alice"'),
  ],
)

Handling Endpoint Variations

Variants in the endpoint must be explicitly declared. For example, /user, /users, /users?by_first_name=Guy are all different. When instantiating, specify any expected variants:

StubOfflineFirstRestResponse<User>(
  endpoints: ["user", "users", "users?by_first_name=Guy"]
)

Stubbing Multiple Models

Rarely will only one model need to be stubbed. All classes in an app can be stubbed efficiently using StubOfflineFirstWithRest:

setUpAll() async {
  final config = {
    User: ['user', 'users'],
    // Even individual member endpoints must be declared for association fetching
    // REST endpoints are manually configured, so the content may vary
    Hat: ['hat/1', 'hat/2', 'hats'],
  }
  final responses = config.entries.map((modelConfig) {
    return modelConfig.value.map((endpoint) {
      return StubOfflineFirstRestResponse.fromFile(
        'api/${modelConfig.key.toString().toLowerCase()}.json',
        endpoint: endpoint,
      );
    });
  }).expand((e) => e);
  final client = StubOfflineFirstWithRest(
    baseEndpoint: 'http://0.0.0.0:3000',
    responses: responses,
  ).client;
}

FAQ

Why can't I declare a model argument?

Due to an open analyzer bug, a custom model cannot be passed to the repository as a type argument.

Unsupported Field Types

• Any unsupported field types from RestProvider, or SqliteProvider
• Future iterables of future models (i.e. Future<List<Future<Model>>>.