Angular 7 库 - 检测到循环依赖（指令、服务、模块）

Question

我用库创建了一个新的 Angular 7 项目。该库包含一个指令、一个服务和一个模块（指令获取注入的服务和在模块中导出的 injectionToken 服务）。我在编译时收到此警告：

WARNING in Circular dependency detected: projects\auth\src\lib\auth.module.ts -> projects\auth\src\lib\login-form-ref.directive.ts -> projects\auth\src\lib\auth.service.ts -> projects\auth\src\lib\auth.module.ts

WARNING in Circular dependency detected: projects\auth\src\lib\auth.service.ts -> projects\auth\src\lib\auth.module.ts -> projects\auth\src\lib\login-form-ref.directive.ts -> projects\auth\src\lib\auth.service.ts

WARNING in Circular dependency detected: projects\auth\src\lib\login-form-ref.directive.ts -> projects\auth\src\lib\auth.service.ts -> projects\auth\src\lib\auth.module.ts -> projects\auth\src\lib\login-form-ref.directive.ts

auth.service.ts

import { Injectable, Inject } from '@angular/core';
import { HttpClient, HttpHeaders, HttpParams, HttpResponse } from '@angular/common/http';
import { Observable } from 'rxjs';
import { map } from 'rxjs/operators';
import { Token } from './models/token';
import { OAuthClient } from './models/oAuthClient';
import { OAUTH_CONFIGURATION } from './auth.module';


@Injectable({
  providedIn: 'root'
})
export class AuthService {
  expectedHttpResponse = 200;

  constructor(
    @Inject(OAUTH_CONFIGURATION) private readonly oAuthClient: OAuthClient
    , private readonly http: HttpClient
  ) { }
...

auth.module.ts

import { NgModule, InjectionToken } from '@angular/core';
import { LoginFormRefDirective } from './login-form-ref.directive';
import { ReactiveFormsModule } from '@angular/forms';
import { OAuthClient } from './models/oAuthClient';
import { HttpClientModule } from '@angular/common/http';

export const OAUTH_CONFIGURATION = new InjectionToken<OAuthClient>('OAUTH_CONFIGURATION');

@NgModule({
  declarations: [LoginFormRefDirective],
  imports: [
    HttpClientModule,
    ReactiveFormsModule
  ],
  exports: [LoginFormRefDirective]
})
export class AuthModule {
  static forRoot(oAuthClientConfig: OAuthClient) {
    return {
      ngModule: AuthModule,
      providers: [
        { provide: OAUTH_CONFIGURATION, useValue: oAuthClientConfig }
      ]
    };
  }
}

登录表单-ref.directive.ts

import { Directive, HostListener, Self, Input } from '@angular/core';
import { FormGroupDirective } from '@angular/forms';
import { Token } from './models/token';
import { AuthService } from './auth.service';

@Directive({
  // tslint:disable-next-line:directive-selector
  selector: '[loginFormRef]'
})
export class LoginFormRefDirective {
  @Input() storeTokenMethod: (token) => void;

  constructor(
    @Self() private readonly formGroup: FormGroupDirective
    , private readonly _authService: AuthService
  ) { }
...

我不知道那个问题的原因...

Answer 1

如错误所述，存在循环依赖：

export const OAUTH_CONFIGURATION = new InjectionToken<OAuthClient>('OAUTH_CONFIGURATION');

其中 OAUTH_CONFIGURATION 从 auth.module 导出，导入到 auth.service，auth.service 导入到 auth.module 和指令。

尝试将注入令牌放入新文件中，然后将其导入 auth.service 和 auth.module。

token.ts:

export const OAUTH_CONFIGURATION = new InjectionToken<OAuthClient>('OAUTH_CONFIGURATION');

其他文件：

import { OAUTH_CONFIGURATION } from './token';

Angular 7 库 - 检测到循环依赖（指令、服务、模块）

Angular 7 Library - Circular Dependency Detected (Directive, Service, Module)

dependency-injection

circular-dependency

angular-directive

angular