我正在关注这个Angular Universal 教程。当我执行此命令时出现错误：
npm run dev:ssr
这是终端窗口的用语：
Compiled successfully.
C:\Users\Denise\Do
cuments\projects\blogangulareight\node_modules\aws-amplify-angular\dist\src\components\authenticator\authentica
tor\authenticator.factory.js:15
import { Component, Input, ViewChild, ComponentFactoryResolver, } from '@angula
r/core';
^
SyntaxError: Unexpected token {
at Module._compile (internal/modules/cjs/loader.js:718:23)
at Object.Module._extensions..js (internal/modules/cjs/loader.js:785:10)
at Module.load (internal/modules/cjs/loader.js:641:32)
at Function.Module._load (internal/mod
ules/cjs/loader.js:556:12)
at Module.require (internal/modules/cjs/loader.js:681:19)
at require (internal/modules/cjs/helpers.js:16:16)
at Object.aws-amplify-angular/dist/src/components/authenticator/authenticator/authenticator.factory (C:\Users\Denise\Documents\projects\blogangulareight\dist\blogangulareight-server\main.js:10726:18)
at __webpack_require__ (C:\Users\Denise\Documents\projects\blogangulareight\dist\blogangulareight-server\main.js:20:30)
at Object../src/app/components/auth/auth.component.ngfactory.js (C:\Users\Denise\Documents\projects\blogangulareight\dist\blogangulareight-server\main.js:8982
:31)
at __webpack_require__ (C:\Users\Denise\Documents\projects\blogangulareight\dist\blogangulareight-server\main.js:20:30)
A server error has occurred.
node exited with 1 code.
connect ECONNREFUSED 127.0.0.1:54811
npm ERR! code ELIFECYCLE
npm ERR! …我有两个组件和一个服务。我想使用该服务来存储一个公共值。StripeComponent设置服务中的值。我收到以下错误：
无法读取未定义的属性“setAddress”
这是我的组件：
import { Component, ViewChild, OnInit } from '@angular/core'
import { NgForm } from '@angular/forms'
import { Address } from '../_models/address'
import { Observable } from 'rxjs';
import { ConfigService } from '../_services/config.service';
declare var Stripe;
@Component({
selector: 'app-stripe',
templateUrl: './stripe.component.html',
styleUrls: ['./stripe.component.css'],
providers: [ConfigService]
})
export class StripeComponent implements OnInit {
public address =
new Address(
{
name:"",
address_city: "",
address_line1: "",
address_line2: "",
address_state: "",
address_zip: "",
address_country: ""
}
)
configService: ConfigService
constructor() …由于多种原因，这不是重复的。1.我使用的是角度7，而不是角度2。2.我使用的是rxjs6，而不是rxjs5。学习这些较早的版本已不存在，我对此无益。3.当这个问题没有提到Observable（boolean）时，我问的是Observable（boolean）概念
我创建了一个Observable值，希望从中得出true / false。这是我在nav.component.ts文件中的代码
export class NavComponent implements OnInit {
private $loggedin: Observable<boolean>;
constructor( private auth: AuthenticationService){}
ngOnInit() {
this.$loggedin = this.auth.$isLoggedinSource;
console.log('am i logged in ', this.$loggedin);
}
控制台输出为：
am i logged in Observable {_isScalar: false, source: BehaviorSubject}
source: BehaviorSubject {_isScalar: false, observers:
Array(0), closed: false, isStopped: false, hasError:
false, …}
_isScalar: false ...
如何从$ loggedin中获取布尔值，真/假值？