markmaynard/cookie-expiry.ts

## cookie-expiry.ts
import { Injectable } from '@angular/core';
import { IdleExpiry } from '@ng-idle/core';

@Injectable()
export class CookieExpiry extends IdleExpiry {
  private lastValue: Date = undefined;
  private baseDomain: string;

  constructor() {
    super();
    this.baseDomain = this.findBaseDomain();
  }

  /*
   * Gets or sets the last expiry date.
   * @param value - The expiry value to set; omit to only return the value.
   * @return The current expiry value.
   */
  last(value?: Date): Date {
    if (value !== void 0 && value !== undefined) {
      // tslint:disable-next-line no-null-keyword
      if (value === null) {
        this.lastValue = undefined;
        // delete cookie
        document.cookie = `idle-timeout=;expires=Thu, 01 Jan 1970 00:00:01 GMT;domain=${this.baseDomain};`;
      } else {
        this.lastValue = value;
        const expireDate = new Date(new Date().setFullYear(new Date().getFullYear() + 1)).toUTCString();
        // set cookie
        document.cookie =
            `idle-timeout=${value.toUTCString()};domain=${this.baseDomain};expires=${expireDate};path=/`;
      }
    } else {
      if (this.getCookie('idle-timeout') !== undefined) {
        this.lastValue = new Date(this.getCookie('idle-timeout'));
      } else {
        this.lastValue = undefined;
      }
    }
    return this.lastValue;
  }

  /*
   * Returns whether or not it is expired.
   * @return True if expired; otherwise, false.
   */
  isExpired(): boolean {
    const expiry = this.last();
    return expiry !== undefined && expiry <= this.now();
  }

  private getCookie(name: string): any {
    const splitCookies = document.cookie.split(';');
    const searchString = `${name}=`;
    for (let i = 0; i < splitCookies.length; i++) {
      const currentCookie = splitCookies[i].trim();
      if (currentCookie.indexOf(searchString) === 0) {
        return currentCookie.substring(searchString.length, currentCookie.length);
      }
    }
    return undefined;
  }

  private findBaseDomain(): string {
    let baseDomain = document.domain;
    const splitDomain = baseDomain.split('.');
    const testCookie = 'base-domain-cookie' + new Date().getTime().toString();
    let i = 0;
    // find root domain by trying to set cookie until it works
    while (i < splitDomain.length - 1 && document.cookie.indexOf(`${testCookie}=${testCookie}`) === -1) {
      baseDomain = splitDomain.slice(-1 - (++i)).join('.');
      document.cookie = `${testCookie}=${testCookie};domain=${baseDomain};`;
    }
    // delete the cookie that worked
    document.cookie = `${testCookie}=;expires=Thu, 01 Jan 1970 00:00:01 GMT;domain=${baseDomain};`;
    return baseDomain;
  }
}