Angular:从惰性功能模块添加多提供者 [英] Angular: add a multi provider from lazy feature module

问题描述

我有一个 ErrorModule (eager) 配置如下:

I have an ErrorModule (eager) configured as follows:

export const CONFIG = new InjectionToken<ErrorConfig[]>('Module errors configuration.');


@NgModule({
  imports: [... ]
})
export class ErrorModule {
  static forRoot(config: ErrorConfig): ModuleWithProviders {
    return {
      ngModule: ErrorModule,
      providers: [
        ErrorService,
        { provide: HTTP_INTERCEPTORS, useClass: ErrorInterceptor, multi: true },
        { provide: CONFIG, useValue: config, multi: true }
      ]
    };
  }

  static forChild(config: ErrorConfig): ModuleWithProviders {
    return {
      ngModule: ErrorModule,
      providers: [
        { provide: CONFIG, useValue: config, multi: true }
      ]
    };
  }
}

核心模块然后按如下方式导入ErrorModule:

Core module then imports ErrorModule as follows:

@NgModule({
  imports: [
    ErrorModule.forRoot(ERROR_CONFIG)
  ], ...

懒惰加载的子功能模块:

@NgModule({
  imports: [
    ErrorModule.forChild(ERROR_CONFIG_CHILD)
  ], ...

我希望看到两个配置ERROR_CONFIG 和ERROR_CONFIG_CHILD 注入到ErrorModule 中定义的ErrorService::

I would like to see both configurations ERROR_CONFIG and ERROR_CONFIG_CHILD injected into ErrorService defined in ErrorModule:

@Injectable
export class ErrorService {
    constructor(@Inject(CONFIG) private readonly errorConfigs: ErrorConfig[])
}

但是服务的 errorConfigs(在构造函数中)只包含 core.module 中定义的 CONFIG - forRoot() 函数(一个元素的数组).

But the service's errorConfigs (in constructor) contains only CONFIG defined in core.module - the one defined in forRoot() function (An array with one element).

已加载和初始化延迟功能模块，并且调用了 ErrorModule.forChild(...)

当只有核心模块的 CONFIG 注入令牌可用时，ErrorService 已及时构建是有道理的 - 功能模块尚未加载.

It kind of makes sense that the ErrorService has been constructed in time when only core module's CONFIG injection token was available - the feature module has not beeen loaded yet.

我还尝试在构造函数之外使用 Angular Injector 导入 CONFIG(ErrorService 中的方法)，结果是一样的.

I have also tried to import the CONFIG using Angular Injector outside of constructor (method in ErrorService) and the result was same.

const configs: any[] = injector.get(CONFIG); // returns only root CONFIG

所以我的问题是:是否有可能以某种方式访问​​ app 模块中的惰性模块提供的提供程序?(在应用的根注入器中访问它?)

So my question is: Is it possible to somehow access a provider provided by a lazy module in app module? (Access it in app's root injector?)

推荐答案

我最终得到了一个解决方案，它使用 CoreModule 中定义的 ErrorService 在 时注册配置>FeatureModule 已初始化:

I ended up with a solution, that uses ErrorService defined in CoreModule to register configurations when FeatureModule is initialized:

import { ErrorService } from '@core/error.service';

@NgModule({
    imports: [ CommonModule, ForFeatureModule, TranslateModule.forChild() ],
    declarations: [FeatureModule],
    providers: []
})
export class FeatureModule {
    constructor(
        private readonly translate: TranslateService, private readonly errorService: ErrorService) {
        translate.setTranslation('cz', i18n, true);

        // --- HERE --- errorService configures global error configuration
        errorService.addErrorMappings('FEATURE1', ERROR_MAPPING);
    }
}

这篇关于Angular:从惰性功能模块添加多提供者的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！