正如 ionic-Angular 3.9.0 发行说明中所述(https://github.com/ionic-team/ionic/blob/master/CHANGELOG.md),利用更新到 RXJS 5.5.2 的优势可以减少捆绑包大小,从而缩短启动时间
酷,酷,酷:)
Ionic 提供的示例,例如迁移
debounceTime
非常清楚,我明白了。
但是我很不清楚应该如何更新以下代码才能充分利用此 RXJS 更新。
任何人都可以帮助我转换它或者如何更好地编写它以节省包大小?
import {Observable} from 'rxjs/Observable';
import 'rxjs/add/observable/empty';
import 'rxjs/add/operator/do';
import 'rxjs/add/operator/catch';
intercept(req: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
return next.handle(req).do((event: HttpEvent<any>) => {
if (event instanceof HttpResponse) {
// do stuff with response if you want
}
}).catch((err: HttpErrorResponse) => {
if ((err.status == 400) || (err.status == 401)) {
this.interceptorRedirectService.getInterceptedSource().next(err.status);
return Observable.empty();
} else {
return Observable.throw(err);
}
})
}
PS:链接帖子https://forum.ionicframework.com/t/how-to-better-catch-do-empty-with-rxjs-5-5-2-updates/111559
我想出了以下仍然有效的更新代码(经过测试)。
import {Observable} from 'rxjs/Observable';
import 'rxjs/add/observable/empty';
import {tap} from 'rxjs/operators/tap';
import {catchError} from 'rxjs/operators/catchError';
intercept(req: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
return next.handle(req).pipe(
tap((event: HttpEvent<any>) => {
if (event instanceof HttpResponse) {
// do stuff with response if you want
}
}),
catchError((err: HttpErrorResponse) => {
if ((err.status == 400) || (err.status == 401)) {
this.interceptorRedirectService.getInterceptedSource().next(err.status);
return Observable.empty();
} else {
return Observable.throw(err);
}
})
);
}
注:
可出租运算符必须使用完整的导入路径导入,以减少包大小
好:从 'rxjs/operators/catchError' 导入 {catchError}; 不好:从 'rxjs/operators' 导入 {catchError};
静态不会改变,它们不可出租(参见https://github.com/ReactiveX/rxjs/issues/3059)
静态只能在所有应用程序的 app.component.ts 中导入一次(这不会减少包大小,但代码会更干净)
基于 David Dal Buscon 的出色回答,我还分别将 Observable.empty 和 Observable.throw 更新为 empty 和 _throw
import {Observable} from 'rxjs/Observable';
import {empty} from 'rxjs/observable/empty';
import {_throw} from 'rxjs/observable/throw';
import {catchError, tap} from 'rxjs/operators';
intercept(req: HttpRequest<any>, next: HttpHandler):
Observable<HttpEvent<any>> {
return next.handle(req)
.pipe(
tap((event: HttpEvent<any>) => {
if (event instanceof HttpResponse) {
// do stuff with response if you want
}
}),
catchError((err: HttpErrorResponse) => {
if ((err.status == 400) || (err.status == 401)) {
this.interceptorRedirectService.getInterceptedSource()
.next(err.status);
return empty();
}
return _throw(err);
})
);
}
Angular 17,RxJS 7.8.1。由于这里几乎不推荐使用所有答案,这就是我返回空 Observable 的方法:
import { catchError, EMPTY } from 'rxjs';
test(): void {
this.testService
.startTestJob()
.pipe(
catchError((err) => {
this.snackIt.addError('error:', err);
return EMPTY;
})
)
.subscribe();
}