Repository Provider

Riverpod provider that wires the MovieRepositoryImpl and MoviedbDataSource together and makes them available to the rest of the app.

movieRepositoryProvider is a Riverpod Provider that constructs the single shared instance of MovieRepositoryImpl for the entire widget tree. All movie-list providers depend on it to reach the TheMovieDB API.

Provider definition

movies_repository_provider.dart

import 'package:cinemapedia_220083/infrastructure/datasources/moviedb_datasource.dart';
import 'package:cinemapedia_220083/infrastructure/repositories/movie_repository_impl.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';

final movieRepositoryProvider = Provider((ref) {
  return MovieRepositoryImpl(MoviedbDataSource());
});

Return type

movieRepositoryProvider is inferred as Provider<MovieRepositoryImpl>. Because MovieRepositoryImpl implements the abstract MoviesRepository contract, consumers only need to depend on the interface.

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Dependency injection pattern

The provider uses constructor injection: MovieRepositoryImpl receives a MoviedbDataSource instance through its constructor. This creates a strict, one-directional dependency chain:

UI (ConsumerWidget)
  └─ ref.watch(movieRepositoryProvider)
       └─ MovieRepositoryImpl          ← infrastructure/repositories/
            └─ MoviedbDataSource       ← infrastructure/datasources/
                 └─ TheMovieDB REST API

Neither the UI nor the notifiers need to know about MoviedbDataSource directly. They interact only through the MoviesRepository abstract interface, which makes it straightforward to swap the data source (e.g. a mock or a local cache) without touching any presentation code.

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MovieRepositoryImpl

MovieRepositoryImpl implements every method declared in the MoviesRepository abstract class by delegating to the injected MoviesDatasource.

movie_repository_impl.dart

class MovieRepositoryImpl implements MoviesRepository {
  final MoviesDatasource datasource;

  MovieRepositoryImpl(this.datasource);

  @override
  Future<List<Movie>> getNowPlaying({int page = 1}) =>
      datasource.getNowPlaying(page: page);

  @override
  Future<List<Movie>> getPopular({int page = 1}) =>
      datasource.getPopular(page: page);

  @override
  Future<List<Movie>> getUpcoming({int page = 1}) =>
      datasource.getUpcoming(page: page);

  @override
  Future<List<Movie>> getTopRated({int page = 1}) =>
      datasource.getTopRated(page: page);

  @override
  Future<List<Movie>> getMexicanMovies({int page = 1}) =>
      datasource.getMexicanMovies(page: page);
}

---

MoviesRepository abstract interface

The domain layer defines the contract that any repository implementation must fulfil. This keeps the presentation and domain layers free of infrastructure details.

movies_repository.dart

abstract class MoviesRepository {
  Future<List<Movie>> getNowPlaying({int page = 1});
  Future<List<Movie>> getPopular({int page = 1});
  Future<List<Movie>> getUpcoming({int page = 1});
  Future<List<Movie>> getTopRated({int page = 1});
  Future<List<Movie>> getMexicanMovies({int page = 1});
}

---

Reading the provider

Movie-list providers watch movieRepositoryProvider and pull individual method references from it:

movies_providers.dart

final nowPlayingMoviesProvider = NotifierProvider<MoviesNotifier, List<Movie>>(
  () => MoviesNotifier(
    (ref) => ref.watch(movieRepositoryProvider).getNowPlaying,
  ),
);

You can also read it directly in a widget when you need an ad-hoc call:

final repository = ref.read(movieRepositoryProvider);
final movies = await repository.getTopRated(page: 2);

Use ref.read (not ref.watch) when calling the repository imperatively inside callbacks or initState. Reserve ref.watch for reactive rebuilds.