src/app/services/rest/rest-error.interceptor.ts

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import {HttpEvent, HttpHandler, HttpInterceptor, HttpRequest} from '@angular/common/http'
import {Injectable} from '@angular/core'
import {Observable, throwError} from 'rxjs'
import {catchError} from 'rxjs/operators'
import {SessionService} from '../session/session.service'

@Injectable()
export class RestErrorInterceptor implements HttpInterceptor {
    constructor(
        private _sessions: SessionService
    ) {
        // No-op.
    }

    intercept(req: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
        return next.handle(req)
            .pipe(
                catchError(err => {
                    this.check(err);

                    return throwError(err)
                })
            )
    }

    private check(err: any): void {
        if (err.status === 401) {
            // Clear session whenever we intercept 401 (means that session got expired).
            this._sessions.clear()
        }
    }
}