带有解析器的 Angular 7 路由不加载组件

Question

我遇到了一个 Angular 7 问题，其中在路由上具有解析器的模块的子组件无法加载。

app-routing.module.ts

{
  path: 'Account',
  loadChildren: './account/account.module#AccountModule'
}

account-routing.module.ts

{
  path: 'Profile',
  component: ProfileComponent,
  resolve: {
    profile: ProfileResolver
  }
}

profile.resolver.ts

@Injectable()
export class ProfileResolver implements Resolve<Profile> {

  constructor(private readonly accountService: AccountService) {
  }

  resolve(route: ActivatedRouteSnapshot, state: RouterStateSnapshot): Observable<Profile> {
    return this.accountService.profile();
  }
}

profile.component.ts

@Component({
⋮
})
export class ProfileComponent implements OnInit {

  model: Profile;

  constructor(private readonly route: ActivatedRoute) {
  }

  ngOnInit(): void {
    this.model = this.route.snapshot.data['profile'] as Profile;
  }
}

account.service.ts

@Injectable()
export class AccountService {

  constructor(protected readonly http: HttpClient) {
  }

  profile(): Observable<Profile> {
    return this.http.get<Profile>(`${environment.apiUrl}/Account/Profile`);
  }
}

行为是，当导航到 /Account/Profile 时，ProfileResolver 被调用，访问服务器，并获得带有 Profile 对象的 200 响应（我可以在“网络”选项卡中看到它），然后... 没有。既不调用constructor 也不调用ProfileComponent 的ngOnInit 方法。

如果我从AccountRoutingModule 中删除ProfileResolver 并直接从ngOnInit 方法中调用AccountService，它就可以工作。但是在等待响应时，模板中存在许多模板解析错误（这就是我想使用resolve 的全部原因）。

我需要做些什么才能使解析器与这些模块一起工作吗？

这也可能与此处描述的问题相同：Angular Router don't load component with resolver

更新：我打开了enableTracing，所以我可以看到发生了什么。这是输出：

Router Event: NavigationStart
NavigationStart(id: 2, url: '/Account/Profile')
NavigationStart {id: 2, url: "/Account/Profile", navigationTrigger: "imperative", restoredState: null}

Router Event: RoutesRecognized
RoutesRecognized(id: 2, url: '/Account/Profile', urlAfterRedirects: '/Account/Profile', state: Route(url:'', path:'') { Route(url:'Account', path:'Account') { Route(url:'Profile', path:'Profile') }  } )
RoutesRecognized {id: 2, url: "/Account/Profile", urlAfterRedirects: "/Account/Profile", state: RouterStateSnapshot}

Router Event: GuardsCheckStart
GuardsCheckStart(id: 2, url: '/Account/Profile', urlAfterRedirects: '/Account/Profile', state: Route(url:'', path:'') { Route(url:'Account', path:'Account') { Route(url:'Profile', path:'Profile') }  } )
GuardsCheckStart {id: 2, url: "/Account/Profile", urlAfterRedirects: "/Account/Profile", state: RouterStateSnapshot}

Router Event: ChildActivationStart
ChildActivationStart(path: '')
ChildActivationStart {snapshot: ActivatedRouteSnapshot}

Router Event: ActivationStart
ActivationStart(path: 'Profile')
ActivationStart {snapshot: ActivatedRouteSnapshot}

Router Event: GuardsCheckEnd
GuardsCheckEnd(id: 2, url: '/Account/Profile', urlAfterRedirects: '/Account/Profile', state: Route(url:'', path:'') { Route(url:'Account', path:'Account') { Route(url:'Profile', path:'Profile') }  } , shouldActivate: true)
GuardsCheckEnd {id: 2, url: "/Account/Profile", urlAfterRedirects: "/Account/Profile", state: RouterStateSnapshot, shouldActivate: true}

Router Event: ResolveStart
ResolveStart(id: 2, url: '/Account/Profile', urlAfterRedirects: '/Account/Profile', state: Route(url:'', path:'') { Route(url:'Account', path:'Account') { Route(url:'Profile', path:'Profile') }  } )
ResolveStart {id: 2, url: "/Account/Profile", urlAfterRedirects: "/Account/Profile", state: RouterStateSnapshot}

所以看起来ResolveEnd 事件永远不会触发。我发现了这个问题：Router's ActivatedRoute data returns empty {} if module is lazy。似乎它可能是相关的，但我不确定我将如何在此处实施该修复。

Answer 1

我再次查阅了Routing & Navigation 指南并更改了我的解析器，使其看起来像在那里一样：

profile.resolver.ts

@Injectable()
export class ProfileResolver implements Resolve<Profile> {

  constructor(private readonly accountService: AccountService) {
  }

  resolve(route: ActivatedRouteSnapshot, state: RouterStateSnapshot): Observable<Profile> {
    return this.accountService.profile().pipe(
      take(1),
      map((profile: Profile) => profile));
  }
}

关键是添加take(1)。没有这个，ResolveEnd 事件永远不会被触发，Router 只会挂起。

Answer 2

我认为你必须订阅解析器承诺

@Component({
⋮
})
export class ProfileComponent implements OnInit {

  model: Profile;

  constructor(private readonly route: ActivatedRoute) {
  }

  ngOnInit(): void {

    this.router.data.subscribe( (data) => { <== here 
      this.model = data as Profile  <== here
    });
  }
}