我正在使用APP_INITIALIZER,就像在
this的答案中推荐的那样,我的服务返回一个承诺,但并不总是等待它解决,我可以看到我的组件console.logging未定义,然后服务记录下载的对象.
我需要该应用程序在加载数据之前不做任何事情.
app.module.ts
import { NgModule,APP_INITIALIZER } from '@angular/core';
import { Http,HttpModule,JsonpModule } from '@angular/http';
import { UserService } from '../services/user.service';
<...>
@NgModule({
imports: [
BrowserModule,FormsModule,JsonpModule,routing
],declarations: [
AppComponent,<...>
],providers: [
<...>
UserService,{provide: APP_INITIALIZER,useFactory: (userServ: UserService) => () => userServ.getUser(),deps: [UserService,Http],multi: true
}
],bootstrap: [AppComponent]
user.service.ts
@Injectable()
export class UserService {
public user: User;
constructor(private http: Http) { }
getUser(): Promise<User> {
console.log('get user called');
var observable= this.http.get('/auth/getuser',{ headers: getHeaders() })
.map(extractData);
observable.subscribe(user => {this.user = user;
console.log(this.user)});
return observable.toPromise();
}
}
尝试以下代码：
getUser(): Promise<User> {
console.log('get user called');
var promise = this.http.get('/auth/getuser',{headers: getHeaders()})
.map(extractData)
.toPromise();
promise.then(user => {
this.user = user;
console.log(this.user);
});
return promise;
}
我面临着同样的问题,使用承诺而不是观察,对我来说是窍门.
