在 Laravel 6、Module 中，自定义验证规则的 message 中翻译不可用的排查(延迟提供者的使用导致)

1、参考：https://www.shuijingwanwq.com/2022/04/26/6341/

2、在一段时间后，突然发现自定义验证规则的 message 中翻译不可用。验证失败时响应的 message 未被翻译。如图1

{
  "errors": [
    {
      "message": "Validation failed for the field [onlineStoreThemeEditorSessionDelete].",
      "extensions": {
        "validation": {
          "sessionId": [
            "online_store_theme_graphql::validation.custom.theme_editor_session.theme_editor_session_id_exists_rule"
          ]
        },
        "category": "validation"
      },
      "locations": [
        {
          "line": 3,
          "column": 3
        }
      ],
      "path": [
        "onlineStoreThemeEditorSessionDelete"
      ],
      "trace": ...
    }
  ],
  "data": {
    "onlineStoreThemeEditorSessionDelete": null
  }
}

3、参考：https://www.shuijingwanwq.com/2022/06/29/6707/ ，当删除 implements DeferrableProvider 后，再清空目录：/bootstrap/cache 后，翻译正常工作。如图2

{
  "errors": [
    {
      "message": "Validation failed for the field [onlineStoreThemeEditorSessionDelete].",
      "extensions": {
        "validation": {
          "sessionId": [
            "The selected session id is invalid."
          ]
        },
        "category": "validation"
      },
      "locations": [
        {
          "line": 3,
          "column": 3
        }
      ],
      "path": [
        "onlineStoreThemeEditorSessionDelete"
      ],
      "trace": ...
    }
  ],
  "data": {
    "onlineStoreThemeEditorSessionDelete": null
  }
}

4、在模块的服务提供者中的现有实现如下

class GraphQlResolverServiceProvider extends ServiceProvider implements DeferrableProvider
{
    /**
     * @return void
     */    public function register()
    {
        $this->registerTranslations();

        // ...
    }
}

5、参考：/vendor/laravel/framework/src/Illuminate/Translation/TranslationServiceProvider.php ，代码调整如下

class GraphQlResolverServiceProvider extends ServiceProvider implements DeferrableProvider
{
    /**
     * @return void
     */    public function register()
    {
        $this->registerLoader();

        $this->app->singleton('translator', function ($app) {
            $loader = $app['translation.loader'];

            // When registering the translator component, we'll need to set the default
            // locale as well as the fallback locale. So, we'll grab the application
            // configuration so we can easily get both of these values from there.
            $locale = $app['config']['app.locale'];

            $trans = new Translator($loader, $locale);

            $trans->setFallback($app['config']['app.fallback_locale']);

            return $trans;
        });

        $this->registerTranslations();

        // ...
    }

    /**
     * Register the translation line loader.
     *
     * @return void
     */    protected function registerLoader()
    {
        $this->app->singleton('translation.loader', function ($app) {
            return new FileLoader($app['files'], $app['path.lang']);
        });
    }

    /**
     * Register translations.
     *
     * @return void
     */    public function registerTranslations()
    {
        $langPath = resource_path('lang/modules/' . $this->moduleNameLower);

        if (is_dir($langPath)) {
            $this->loadTranslationsFrom($langPath, $this->moduleNameLower);
        } else {
            $this->loadTranslationsFrom(__DIR__ . '/../Resources/lang', $this->moduleNameLower);
        }
    }

    /**
     * 获取由提供者提供的服务。
     *
     * @return array
     */    public function provides()
    {
        return ['translator', 'translation.loader'];
    }
}

6、翻译正常运行。但是这样的话，感觉代码冗余得厉害。决定再次调整一下，将延迟加载的服务单独剥离出一个类。

class OnlineStoreThemeGraphQLServiceProvider extends ServiceProvider
{
    private $moduleNameLower = 'online_store_theme_graphql';

    /**
     * @return void
     */    public function register()
    {
        $this->app->register(ResolverServiceProvider::class);

        $this->registerTranslations();
    }

    /**
     * Register translations.
     *
     * @return void
     */    public function registerTranslations()
    {
        $langPath = resource_path('lang/modules/' . $this->moduleNameLower);

        if (is_dir($langPath)) {
            $this->loadTranslationsFrom($langPath, $this->moduleNameLower);
        } else {
            $this->loadTranslationsFrom(__DIR__ . '/../Resources/lang', $this->moduleNameLower);
        }
    }

    /**
     * 获取由提供者提供的服务。
     *
     * @return array
     */    public function provides()
    {
        return [];
    }
}

class ResolverServiceProvider extends ServiceProvider implements DeferrableProvider
{
    /**
     * Register the service provider.
     *
     * @return void
     */    public function register()
    {
        $this->app->singleton(SettingPersistenceInterface::class, function($app){
            return new DbSettingPersister();
        });

        $this->app->singleton(ThemeAssetRepositoryInterface::class, function($app){
            return new ThemeAssetRepository();
        });
    }

    /**
     * Get the services provided by the provider.
     *
     * @return array
     */    public function provides()
    {
        return [SettingPersistenceInterface::class, ThemeAssetRepositoryInterface::class];
    }
}

7、翻译正常工作。如图3