An Angular (> 4.3) interceptor to parse dates from server response.

AngularDateHttpInterceptor.ts

/**
 * Recursively walk HttpResponse object to cast ISO 8601-formatted dates as
 * Moment.js objects.
 *
 * @see https://git.io/fNzJw
 * @see https://www.npmjs.com/package/is-iso-date
 * @see https://www.npmjs.com/package/traverse
 */

import { Injectable } from '@angular/core';
import { Observable } from 'rxjs/Observable';
import 'rxjs/add/operator/do';

import * as moment from 'moment';
import isIsoDate from 'is-iso-date';
import traverse from 'traverse';

import {
  HttpErrorResponse,
  HttpEvent, HttpHandler,
  HttpInterceptor,
  HttpRequest,
  HttpResponse
} from '@angular/common/http';

@Injectable()
export class AngularDateHttpInterceptor implements HttpInterceptor {
  private static castDateAsMoment(event: HttpEvent<any>): void {
    if (event instanceof HttpResponse) {
      traverse(event.body).forEach(function(value: any): void {
        if (isIsoDate(value)) {
          this.update(moment(value), true);
        }
      });
    }
  }

  intercept(req: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
    return next.handle(req).do(AngularDateHttpInterceptor.castDateAsMoment);
  }
}