angular-date-http-interceptor.ts

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

@Injectable()
export class DateHttpInterceptor implements HttpInterceptor {
  // Migrated from AngularJS https://raw.githubusercontent.com/Ins87/angular-date-interceptor/master/src/angular-date-interceptor.js
  private static iso8601Date = /^\d{4}-\d\d-\d\d?$/;
  private static iso8601DateTime = /^\d{4}-\d\d-\d\dT\d\d:\d\d:\d\d(\.\d+)?(([+-]\d\d:\d\d)|Z)?$/;

  intercept(req: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
    return next.handle(req).pipe(
      map(e => {
        if (e instanceof HttpResponse) {
          const body = e.body;
          this.convertToDate(body);
        }

        return e;
      })
    );
  }

  convertToDate(body) {
    if (body === null || body === undefined) {
      return body;
    }

    if (typeof body !== 'object') {
      return body;
    }

    for (const key of Object.keys(body)) {
      const value = body[key];
      if (this.isIso8601(value)) {
        body[key] = new Date(value);
      } else if (typeof value === 'object') {
        this.convertToDate(value);
      }
    }
  }

  isIso8601(value) {
    if (value === null || value === undefined) {
      return false;
    }

    return DateHttpInterceptor.iso8601Date.test(value) || DateHttpInterceptor.iso8601DateTime.test(value);
  }
}