如何 return promise 函数中的 Observable

Question

我用 ionic + capacitor + angular 写了一个 http 拦截器。因为我使用的是电容器，所以我正在访问 promise 函数中的存储。但是 http 拦截器将我们排除在 return HttpEvent Observable 之外。这是我的代码

import { Injectable } from '@angular/core';
import { HttpInterceptor, HttpHandler, HttpRequest, HttpEvent, HttpResponse } from '@angular/common/http';
import { Observable } from 'rxjs';
import { map } from 'rxjs/operators';

import { Plugins } from '@capacitor/core';

const { Storage } = Plugins;

@Injectable()
export class Interceptor implements HttpInterceptor {
    constructor() { }

    intercept(request: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {

        this.getItem().then(value => {
            const token = value['value'];
            if (token) {
                request = request.clone({ headers: request.headers.set('Authorization', 'Bearer ' + token) });
            }
            if (!request.headers.has('Content-Type')) {
                request = request.clone({ headers: request.headers.set('Content-Type', 'application/json') });
            }
            request = request.clone({ headers: request.headers.set('Accept', 'application/json') });
            return next.handle(request).pipe(
                map((event: HttpEvent<any>) => {
                    if (event instanceof HttpResponse) {
                    }
                    return event;
                }));
        });
    }

    async getItem() {
        return await Storage.get({ key: 'revolt-token' });
    }
}

到目前为止我已经试过了

return from(this.getItem()).pipe(map(data => {
            return next.handle(request).pipe(
                map((event: HttpEvent<any>) => {
                    if (event instanceof HttpResponse) {
                    }
                    return event;
                }));
        });

但是 returns Observable<Observable<HttpEvent<any>>> 但我想要 Observable<HttpEvent<any>>

谁能帮我确定如何从 Promise 中 return Observable。谢谢。

Answer 1

答案是pipe switchMap而不是map 在 return from(this.getItem()).pipe(map(data => {}));

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