/* error handler that will be used below in pipe with catchError()
* when resource fetched with HttpClient get() */
private _handleError<T> (operation: string, result?:T) {
return( error: any): Observable<T> => {
console.error( operation + ' ' + error.message );
// or something else I want to do
return of(result as T); // lets me return innocuous results
}
}
getObjects() {
return this.http.get<any[]>(this.myUrl).pipe(
catchError(this._handleError('my error', [])
);
}
正在使用 tap
处理错误getObjects() {
return this.http.get<any[]>(this.myUrl).pipe(
tap( objects => {
// whatever action like logging a message for instance
}, err => {
console.error(err);
// whatever else I want to do
})
);
}
为什么我应该选择一种方法而不是另一种方法?将使用 tap()
处理 HTTP 错误保持我的应用程序运行以防它们发生?
最佳答案
tap
是造成副作用。catchError
是在流中捕获错误并尝试处理它们。
因此,如果您想处理 http
的错误请求使用 catchError
.
http.get('https://test.com/').pipe(
tap(
() => {
// 200, awesome!, no errors will trigger it.
},
() => {
// error is here, but we can only call side things.
},
),
catchError(
(error: HttpErrorResponse): Observable<any> => {
// we expect 404, it's not a failure for us.
if (error.status === 404) {
return of(null); // or any other stream like of('') etc.
}
// other errors we don't know how to handle and throw them further.
return throwError(error);
},
),
).subscribe(
response => {
// 200 triggers it with proper response.
// 404 triggers it with null. `tap` can't make 404 valid again.
},
error => {
// any error except 404 will be here.
},
);
关于rxjs - 选择哪个 RxJS 操作符来处理 HTTP 错误 : tap or catchError?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/52797992/