Angular：针对特定情况进行不同处理的 HttpInterceptor

Question

我知道 Angular HTTPInterceptor:

@Injectable()
export class HTTPRequestInterceptor implements HttpInterceptor {

intercept(request: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
    return next.handle(request).pipe(
      tap(
        (_response: HttpEvent<any>) => {
          // nothing to do ... ... used for sending anyway...
        },
        (error: HttpErrorResponse) => {
         ... // display message
        }

据我了解，这适用于我的所有请求。现在我的情况是，对于一个特定的请求，我不想应用常规的错误处理。有没有一种简单的方法可以实现这一目标？例如在我的请求中设置一些特殊参数

this.http.get<MyInfo>(`getlastInfo/${id}`).toPromise();

Answer 1

这可能是一种脆弱的方法，但一种方法可能是检查拦截器中的 URL 并有条件地执行拦截器中的逻辑。

@Injectable()
export class HTTPRequestInterceptor implements HttpInterceptor {

intercept(request: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
    return next.handle(request).pipe(
      tap(
        (_response: HttpEvent<any>) => {
          // nothing to do ... ... used for sending anyway...
        },
        (error: HttpErrorResponse) => {
            if(req.url === "some_url"){
                //handle error for specific case
            }else{
                //handle error for generic case
            }
        }
      )
    );
}

Answer 2

一种简单但肮脏的方式

@Injectable()
export class HTTPRequestInterceptor implements HttpInterceptor {

intercept(request: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
 if(req.url.contains('getlastInfo')){
 //specific handling
 } else {
  //normal handling
 }

}

您还可以使用 req.body 或 req.headers 进行检查，方法是在 header.

中设置特定键值等

Answer 3

正如 BELLIL 所建议的，阅读 header 比依赖 url 更容易。您仍然可以在将 header 发送到服务器之前将其删除：

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

    const doSpecificHandling = req.headers.has('Angular-Error-Handler');

    return next.handle(req.clone({
      headers: req.headers.delete('Angular-Error-Handler')
    })).pipe(
      tap(
        (_response: HttpEvent<any>) => {
          // nothing to do ... ... used for sending anyway...
        },
        (error: HttpErrorResponse) => {
          if (doSpecificHandling) {
            //handle error for specific case
          } else {
            //handle error for generic case
          }
        }
      )
    );
  }

随着请求：

this.http.get<MyInfo>(`getlastInfo/${id}`, {
  headers: new HttpHeaders().set('Angular-Error-Handler', 'diff'),
}).toPromise();

Angular：针对特定情况进行不同处理的 HttpInterceptor

Angular: HttpInterceptor with different handling for specific situation

angular-http-interceptors

angular