替换rxjs6中的share()函数 [英] Replacing the share() function for in rxjs6

问题描述

我正在尝试将登录用户的详细信息提供给我的应用程序.我有以下在Angular 5中工作的代码，但在Angular 6中不工作，因为rxjs 6中缺少.share()函数

I'm trying to have the details of the logged in user available to my application. I have the following code which worked in Angular 5, but doesn't work in Angular 6 because the .share() function is missing in rxjs 6

我需要.share()函数吗?关于rxjs 6的更改，我的代码看起来还可以吗?

Do I need the .share() function? Does my code look ok with regards to the changes for rxjs 6?

export class UserService {

    readonly baseUrl = `${environment.apiUrl}/auth`;

    private loggedIn = false;

    private currentUserSubject = new BehaviorSubject<LoggedInUser>({} as LoggedInUser);
    currentUser = this.currentUserSubject.asObservable().share();


    constructor(private http: HttpClient) { }

    login(userLogin: UserLogin) {
        return this.http.post<any>(this.baseUrl + '/login', { username: userLogin.email, password: userLogin.password })
            .subscribe(result => {
                localStorage.setItem('auth_token', result.auth_token);
                this.setCurrentUser();
                return true;
            });
    }

    setCurrentUser(): void {
        if (localStorage.getItem("auth_token")) {
            let jwtData = localStorage.getItem("auth_token").split('.')[1]
            let decodedJwtJsonData = window.atob(jwtData)
            let decodedJwtData = JSON.parse(decodedJwtJsonData)
            this.currentUserSubject.next(
                {
                    firstName: decodedJwtData.given_name,
                    id: decodedJwtData.id,

                }
            );
        }
    }

    getCurrentUser(): LoggedInUser {
        if (this.currentUserSubject.value.id) {
            return this.currentUserSubject.value;
        }
    }

    ngOnDestroy() {
        this.currentUserSubject.unsubscribe();
    }

    isLoggedIn() {
        this.setCurrentUser();
        if (this.currentUserSubject.value.id) {
            return true;
        }
        return false;
    }

}

推荐答案

RxJS v5.5.2 + 已移至 Pipeable 运算符，以改善树抖动并使其更易于创建自定义运算符.现在，需要使用 pipe 方法将 operator 组合起来

RxJS v5.5.2+ has moved to Pipeable operators to improve tree shaking and make it easier to create custom operators. now operators need to be combined using the pipe method
Refer This
New Import

import { share} from 'rxjs/operators';

修改后的代码

   currentUser = this.currentUserSubject.asObservable().pipe(share());

RxJS 6-发生了什么变化?有什么新功能?

我需要.share()函数吗?

Do I need the .share() function?

取决于您的用例，如果您不使用多个异步 pipe ，则不需要 share 运算符
Subject 充当源 Observable 和许多 observers 之间的桥梁/代理，这使得多个 observers 可以共享相同的 Observable 执行.

Depends on your use case, if you aren't using multiple async pipe you don't require share operator
Subject acts as a bridge/proxy between the source Observable and many observers, making it possible for multiple observers to share the same Observable execution.

异步管道不使用共享，也没有对模板中的多次重复使用进行任何优化.它会为模板中Async管道的每次使用创建一个订阅.

引用 : RxJS:了解发布和共享运营商

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