nbr

Description:

nbr

nbr #
nbr (Network Bound Resource) is a Dart library for managing resources that are bound to network requests. It simplifies the handling of data fetching from network and local storage, ensuring a consistent and reactive approach to resource management.
Features #

Manages network requests and local storage seamlessly.
Emits stream updates for different states: loading, success, failed, and empty.
Provides a structured way to handle data fetching, caching, and mapping.

Installation #
Add nbr to your pubspec.yaml file:
dependencies:
nbr: latest
copied to clipboard
Then, run pub get to install the package.
Usage #
Import the library:
import 'package:nbr/nbr.dart';
copied to clipboard
Example #
class MyNetworkBoundResource extends NetworkBoundResource<MyEntity> {
Future<void> fetchData() async {
await fetch<MyDTO>(
fetchFromAPI: () async {
// Implement your API call here
return MyDTO();
},
loadFromDB: () async {
// Implement loading data from the database
return null;
},
storeToDB: (data) async {
// Implement storing data to the database
},
shouldFetch: (data) async {
// Implement your logic to decide whether to fetch from API
return true;
},
mapDTOToEntity: (dto) {
// Implement mapping from DTO to entity
return MyEntity();
},
);
}
}

void main() async {
final resource = MyNetworkBoundResource();

resource.stream.listen((resource) {
if (resource.isLoading) {
print('Loading...');
} else if (resource.isSuccess) {
print('Success: ${resource.data}');
} else if (resource.isFailed) {
print('Failed: ${resource.error}');
} else if (resource.isEmpty) {
print('No data');
}
});

await resource.fetchData();
}
copied to clipboard
API #
NetworkBoundResource<Entity> #
Abstract class representing a resource bound to a network request.
Properties

Stream<Resource<Entity>> get stream: A stream of Resource objects representing the current state of the resource.

Methods


Future<void> fetch<DTO>(...): Fetches the resource from the network and emits Resource objects representing the current state.

fetchFromAPI: A callback to fetch the resource from the API.
loadFromDB: A callback to load the resource from the database.
storeToDB: A callback to store the fetched resource to the database.
shouldFetch: A callback to determine if the resource should be fetched from the API.
mapDTOToEntity: A callback to map the DTO from the API to an entity.



void dispose(): Disposes of the NetworkBoundResource by closing the StreamController.


Resource<T> #
A class representing the state of a resource.
Properties

bool get isLoading: Indicates if the resource is in a loading state.
bool get isSuccess: Indicates if the resource has been successfully fetched.
bool get isFailed: Indicates if the resource fetching has failed.
bool get isEmpty: Indicates if the resource is empty.
T? data: The data of the resource.
Object? error: The error occurred during fetching the resource.

Static Methods

Resource<T> loading([T? data]): Creates a loading state.
Resource<T> success(T data): Creates a success state.
Resource<T> failed(Object error): Creates a failed state.
Resource<T> empty(): Creates an empty state.