'useValue' 提供者的 Angular 4 静态分析失败

Question

我收到这个错误 -

错误:错误:静态解析符号值时遇到错误。调用函数“SecurityModule”，不支持函数调用。考虑用导出函数的引用替换函数或 lambda ...


我读到函数调用不能太复杂以至于静态分析器无法处理，但您可以看到这应该是直截了当的。我不确定为什么会失败。
我看过几个使用长格式提供者对象的示例，据我所知，这应该是可以接受的。

这是项目-
https://github.com/savantly-net/ngx-security

有什么想法吗？

安全模块 -

import { ISecurityService } from './ISecurity.service';
import { NgModule, ModuleWithProviders, Optional, SkipSelf, InjectionToken } from '@angular/core';
import { CommonModule } from '@angular/common';
import { UserComponent } from './user/user.component';

export const SECURITY_SERVICE = new InjectionToken<ISecurityService>('security.service');

@NgModule({
  imports: [
    CommonModule
  ],
  exports: [ UserComponent ],
  declarations: [ UserComponent ]
})
export class SecurityModule {

  static forRoot(securityService: ISecurityService): ModuleWithProviders {
    return {
      ngModule: SecurityModule,
      providers: [{
        provide: SECURITY_SERVICE,
        useValue: securityService
      }]
    };
  }

  constructor (@Optional() @SkipSelf() parentModule: SecurityModule) {
    if (parentModule) {
      throw new Error(
        'SecurityModule is already loaded. Import it in the AppModule only');
    }
  }
}

应用模块 -

import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';

import { AppComponent } from './app.component';
import { SecurityModule, SecurityMockService } from '@savantly/ngx-security';

export const mockSecurity = new SecurityMockService();

@NgModule({
  declarations: [
    AppComponent
  ],
  imports: [
    BrowserModule,
    SecurityModule.forRoot(mockSecurity)
  ],
  providers: [],
  bootstrap: [AppComponent]
})
export class AppModule { }

SecurityMockService -

@Injectable()
export class SecurityMockService implements ISecurityService {
  logout: () => void;
  login: (username: string, password: string) => boolean;
  user: IUser;

  constructor() {
    this.user = {
      principal: 'demoUser',
      displayName: 'Demo User',
      authenticated: false,
      roles: ['ADMIN', 'USER']
    };

    this.login = (_username: string, _password: string) => {
      this.user.authenticated = true;
      return true;
    };

    this.logout = () => {
      this.user.authenticated = false;
    };
  }
}

Answer 1

好的，这是简单的解决方法:

使用 SecurityModule.forRoot(new SecurityMockService()) 而不是

export const mockSecurity = new SecurityMockService();
SecurityModule.forRoot(mockSecurity)

但是来了。你真的应该像 Graham 说的那样使用 useClass，因为这会让你的服务实例化成为 Angular 。