custom assets loaders for easy_localization

…0 and flutter_svg 0.18.0 depends on xml ^4.1.0, easy_localization_loader >=0.0.1 is incompatible with flutter_svg 0.18.0. So, because qanuni_mobile_app depends on both flutter_svg 0.18.0 and easy_localization_loader 0.0.2, version solving failed.

Because no versions of easy_localization_loader match >0.0.2 <0.1.0 and easy_localization_loader 0.0.2 depends on xml ^3.5.0, easy_localization_loader ^0.0.2 requires xml ^3.5.0. Because flutter_svg >=0.18.1 depends on xml ^4.2.0 and flutter_svg >=0.18.0 <0.18.1 depends on xml ^4.1.0, flutter_svg >=0.18.0 requires xml ^4.1.0. Thus, easy_localization_loader ^0.0.2 is incompatible with flutter_svg >=0.18.0. So, because cip depends on both flutter_svg ^0.18.0 and easy_localization_loader ^0.0.2, version solving failed. Running "flutter pub get" in cip...
pub get failed (1; So, because cip depends on both flutter_svg ^0.18.0 and easy_localization_loader ^0.0.2, version solving failed.)

Purpose

• add new class SmartNetworkAssetLoader that able to fetch localization using online .json files from provided url.
• add configurable cache from network assets using Duration(..) class
• add Failover system to local assets when there is a failure when fetching the online .json and no caches stored
• inspired by and resolved #30 , #29 , #17

Types of changes

What types of changes does your code introduce? Put an x in the boxes that apply

• [ ] Bugfix (non-breaking change which fixes an issue)
• [X] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
• [ ] Documentation Update (if none of the other choices apply)

How to Test

Just use this class in the assetLoader attribute of EasyLocalization and configure it as you want

SmartNetworkAssetLoader(
          assetsPath: 'assets/translations',
          localCacheDuration: Duration(days: 1),
          localeUrl: (String localeName) => Constants.appLangUrl,
          timeout: Duration(seconds: 30)
)

Environment

Please define your environment to test this, you can choose multiple options. Put an x in the boxes that apply

• [X] Production
• [X] Development
• [X] Testing
• [X] Android
• [X] iOS

[✓] Flutter (Channel stable, 2.5.3, on macOS 12.3.1 21E258 darwin-arm, locale en-ID)
    • Flutter version 2.5.3 at /Users/ariefwijaya/fvm/versions/2.5.3
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision 18116933e7 (6 months ago), 2021-10-15 10:46:35 -0700
    • Engine revision d3ea636dc5
    • Dart version 2.14.4

 [✓] Android toolchain - develop for Android devices (Android SDK version 33.0.0-rc2)
    • Android SDK at /Users/ariefwijaya/Library/Android/sdk
    • Platform android-31, build-tools 33.0.0-rc2
    • Java binary at: /Applications/Android Studio.app/Contents/jre/Contents/Home/bin/java
    • Java version OpenJDK Runtime Environment (build 11.0.11+0-b60-7772763)
    • All Android licenses accepted.

[✓] Xcode - develop for iOS and macOS
    • Xcode at /Applications/Xcode.app/Contents/Developer
    • Xcode 13.3.1, Build version 13E500a
    • CocoaPods version 1.11.2

[✓] Chrome - develop for the web
    • Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome

[✓] Android Studio (version 2021.1)
    • Android Studio at /Applications/Android Studio.app/Contents
    • Flutter plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/9212-flutter
    • Dart plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/6351-dart
    • Java version OpenJDK Runtime Environment (build 11.0.11+0-b60-7772763)

[✓] IntelliJ IDEA Community Edition (version 2020.3.4)
    • IntelliJ at /Applications/IntelliJ IDEA CE.app
    • Flutter plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/9212-flutter
    • Dart plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/6351-dart

[✓] VS Code (version 1.66.2)
    • VS Code at /Applications/Visual Studio Code.app/Contents
    • Flutter extension version 3.38.1

[✓] Connected device (1 available)
    • Chrome (web) • chrome • web-javascript • Google Chrome 100.0.4896.127

• No issues found!

Expected Results

1. able to fetch localization data from provided url, otherwise get data from assetsPath
2. When the data has been fetched, it can be use even in offline because caches system

Sometimes it's needed to specify additional parameters for an HTTP request. In my case I need to pass an api token in the header to be able to get access to my localization service (Localizely). Currently the loader takes String URL. I think it would be better to change it to HTTP object instead, so user can shape the request as he\she needs. Just a suggestion.

Hello, I wanted to update the libraries I installed on my mobile application, but when I put the latest version of http, it tells me that easy_localization_loader is dependent on http ^0.12.0+2

Here is the entire error:

Because every version of easy_localization_loader depends on http ^0.12.0+2 and hover depends on http ^0.13.0, easy_localization_loader is forbidden.

So, because hover depends on easy_localization_loader ^0.0.2, version solving failed.
pub get failed (1; So, because hover depends on easy_localization_loader ^0.0.2, version solving failed.)
exit code 1

Can you change the version of http?

https://github.com/aissat/easy_localization_loader/blob/master/lib/src/json_asset_loader.dart

I do not understand how you can load data from json file as the json asset_loader is not implemented?

Maybe the file asset loader is more appropriate as it contain "jsondecode" ?

https://github.com/aissat/easy_localization_loader/blob/master/lib/src/file_asset_loader.dart

I want to solve this issue please.....

this library can be support getting locale from network when its available?

it seems this class don't work correctly and i get some error. reference

final String assetsLocalePath = 'assets/langs/';
    runApp(EasyLocalization(
      path: assetsLocalePath,
      useOnlyLangCode: true,
      child: MyApp(),
      assetLoader: AssetOrNetworkAssetLoader(
          assetsPath: assetsLocalePath,
          localCacheDuration: Duration(days: 1), // how long the localizations file should be kept
          localeUrl: (String localeName) =>  'http://example.com/$localeName'), // the URL for the remote locale file
      supportedLocales:
          supportedLocales.map((locale) => Locale(locale)).toList(),

The loader:

import 'dart:async';
import 'dart:convert';
import 'dart:io';

import 'package:connectivity/connectivity.dart';
import 'package:easy_localization/easy_localization.dart';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:http/http.dart' as http;
import 'package:path_provider/path_provider.dart';

const defaultTimeout = Duration(seconds: 1);

class AssetOrNetworkAssetLoader extends AssetLoader {
  /// The local URL method which accepts a [localeName] and returns the full distant
  /// localUrl
  final Function localeUrl;

  /// The timeout for downloading the distant localization files
  final Duration timeout;

  /// The default path for assets json files
  final String assetsPath;

  /// The duration before refreshing local localizations files with distant ones
  final Duration localCacheDuration;

  AssetOrNetworkAssetLoader(
      {@required this.localeUrl,
      this.timeout,
      this.assetsPath,
      this.localCacheDuration});

  @override
  Future<Map<String, dynamic>> load(String localePath) async {
    String string;
    String localeName =
        localePath.replaceFirst(assetsPath, '').replaceFirst('.json', '');

    // try loading local previously-saved localization file
    if (await localTranslationExists(localeName)) {
      string = await loadFromLocalFile(localeName);
    }

    // no local or failed, check if internet and download the file
    if (string == null && await isInternetConnectionAvailable()) {
      string = await loadFromNetwork(localeName);
    }

    // local cache duration was reached or no internet access but prefer local file to assets
    if (string == null &&
        await localTranslationExists(localeName, ignoreCacheDuration: true)) {
      string = await loadFromLocalFile(localeName);
    }

    // still nothing? Load from assets
    if (string == null) {
      string = await rootBundle.loadString(localePath);
    }

    // then returns the json file
    return json.decode(string);
  }

  @override
  Future<bool> localeExists(String localePath) => Future.value(true);

  Future<bool> isInternetConnectionAvailable() async {
    ConnectivityResult connectivityResult =
        await (Connectivity().checkConnectivity());
    if (connectivityResult == ConnectivityResult.none) return false;

    final result = await Future.any([
      InternetAddress.lookup('example.com'),
      Future.delayed(timeout ?? defaultTimeout)
    ]);

    if (result.isNotEmpty && result[0].rawAddress.isNotEmpty) {
      return true;
    }

    return false;
  }

  Future<String> loadFromNetwork(String localeName) async {
    String url = localeUrl(localeName);

    try {
      final response = await Future.any(
          [http.get(url), Future.delayed(timeout ?? defaultTimeout)]);

      if (response != null && response.statusCode == 200) {
        String content = response.body.toString();

        // check valid json before saving it
        if (json.decode(content) != null) {
          await saveTranslation(localeName, content);
          return content;
        }
      }
    } catch (e) {
      print(e.toString());
    }

    return null;
  }

  Future<bool> localTranslationExists(String localeName,
      {bool ignoreCacheDuration: false}) async {
    File translationFile = await getFileForLocale(localeName);

    if (!await translationFile.exists()) {
      return false;
    }

    // don't check file's age
    if (!ignoreCacheDuration) {
      Duration difference =
          DateTime.now().difference(await translationFile.lastModified());

      if (difference > (localCacheDuration ?? Duration(days: 1))) {
        return false;
      }
    }

    return true;
  }

  Future<String> loadFromLocalFile(String localeName) async {
    return await (await getFileForLocale(localeName)).readAsString();
  }

  Future<void> saveTranslation(String localeName, String content) async {
    File file = await new File(await getFilenameForLocale(localeName))
        .create(recursive: true);
    return file.writeAsString(content);
  }

  Future<String> get _localPath async {
    final directory = await getTemporaryDirectory();

    return directory.path;
  }

  Future<String> getFilenameForLocale(String localeName) async {
    return "${await _localPath}/langs$localeName.json";
  }

  Future<File> getFileForLocale(String localeName) async {
    return File(await getFilenameForLocale(localeName));
  }
}

• multiple and single yaml parser
• multiple and single xml parser
• readme and changelog
• logs

i prepare pubspec to easy locale 2.2.0, if need test change to 2.2.0-dev

Hi, I am try to call assetLoader: HttpAssetLoader() but HttpAssetLoader() is undefined. I added easy_localization and easy_localization_loader in ymal but still not reading. Need your response. Thank you

• multiple and single yaml parser
• multiple and single xml parser
• readme and changelog
• logs

i prepare pubspec to easy locale 2.2.0, if need test change to 2.2.0-dev

I started to get errors with the last update due to auto detection of csv settings. I use ; as fieldDelimiter and ” as textDelimiter. Either these should be added or the library should be extendable.

auto_router depends on xml 6.0.1 while this package depends on 5.0.2, which causes incompatibility with xml dependency. Please, upgrade your xml dependency.

if you are in need of a particular type of requirement such as:

your translations in the asset are not complete so you want to use the remote translations but want to make them available for offline use. this makes the app useable if there is no internet connection to fetch the new translations every time.

if there is translation file locally(cached) then

1. merge the local translation file with the asset-bundler translation file but give priority to the local translation.
2. if the local localization is older than [one day] then fetch the new localization from backend and save in local(cache) and perform 1st step.