notifications-admin/app/assets/javascripts/govuk/cookie-functions.js

// used by the cookie banner component

(function (root) {
  'use strict';
  window.GOVUK = window.GOVUK || {};

  var DEFAULT_COOKIE_CONSENT = {
    'analytics': false
  };

  var COOKIE_CATEGORIES = {
    '_ga': 'analytics',
    '_gid': 'analytics'
  };

  /*
    Cookie methods
    ==============

    Usage:

      Setting a cookie:
      GOVUK.cookie('hobnob', 'tasty', { days: 30 });

      Reading a cookie:
      GOVUK.cookie('hobnob');

      Deleting a cookie:
      GOVUK.cookie('hobnob', null);
  */
  window.GOVUK.cookie = function (name, value, options) {
    if (typeof value !== 'undefined') {
      if (value === false || value === null) {
        return window.GOVUK.setCookie(name, '', { days: -1 });
      } else {
        // Default expiry date of 30 days
        if (typeof options === 'undefined') {
          options = { days: 30 };
        }
        return window.GOVUK.setCookie(name, value, options);
      }
    } else {
      return window.GOVUK.getCookie(name);
    }
  };

  window.GOVUK.getConsentCookie = function () {
    var consentCookie = window.GOVUK.cookie('cookies_policy');
    var consentCookieObj;

    if (consentCookie) {
      try {
        consentCookieObj = JSON.parse(consentCookie);
      } catch (err) {
        return null;
      }

      if (typeof consentCookieObj !== 'object' && consentCookieObj !== null) {
        consentCookieObj = JSON.parse(consentCookieObj);
      }
    } else {
      return null;
    }

    return consentCookieObj;
  };

  window.GOVUK.setConsentCookie = function (options) {
    var cookieConsent = window.GOVUK.getConsentCookie();

    if (!cookieConsent) {
      cookieConsent = JSON.parse(JSON.stringify(DEFAULT_COOKIE_CONSENT));
    }

    for (var cookieType in options) {
      cookieConsent[cookieType] = options[cookieType];

      // Delete cookies of that type if consent being set to false
      if (!options[cookieType]) {
        for (var cookie in COOKIE_CATEGORIES) {
          if (COOKIE_CATEGORIES[cookie] === cookieType) {
            window.GOVUK.cookie(cookie, null);

            if (window.GOVUK.cookie(cookie)) {
              document.cookie = cookie + '=;expires=' + new Date() + ';domain=' + window.location.hostname.replace(/^www\./, '.') + ';path=/';
            }
          }
        }
      }
    }

    window.GOVUK.setCookie('cookies_policy', JSON.stringify(cookieConsent), { days: 365 });
  };

  window.GOVUK.checkConsentCookieCategory = function (cookieName, cookieCategory) {
    var currentConsentCookie = window.GOVUK.getConsentCookie();

    // If the consent cookie doesn't exist, but the cookie is in our known list, return true
    if (!currentConsentCookie && COOKIE_CATEGORIES[cookieName]) {
      return true;
    }

    currentConsentCookie = window.GOVUK.getConsentCookie();

    // Sometimes currentConsentCookie is malformed in some of the tests, so we need to handle these
    try {
      return currentConsentCookie[cookieCategory];
    } catch (e) {
      console.error(e);
      return false;
    }
  };

  window.GOVUK.checkConsentCookie = function (cookieName, cookieValue) {
    // If we're setting the consent cookie OR deleting a cookie, allow by default
    if (cookieName === 'cookies_policy' || (cookieValue === null || cookieValue === false)) {
      return true;
    }

    if (COOKIE_CATEGORIES[cookieName]) {
      var cookieCategory = COOKIE_CATEGORIES[cookieName];

      return window.GOVUK.checkConsentCookieCategory(cookieName, cookieCategory);
    } else {
      // Deny the cookie if it is not known to us
      return false;
    }
  };

  window.GOVUK.setCookie = function (name, value, options) {
    if (window.GOVUK.checkConsentCookie(name, value)) {
      if (typeof options === 'undefined') {
        options = {};
      }
      var cookieString = name + '=' + value + '; path=/';
      if (options.days) {
        var date = new Date();
        date.setTime(date.getTime() + (options.days * 24 * 60 * 60 * 1000));
        cookieString = cookieString + '; expires=' + date.toGMTString();
      }
      if (document.location.protocol === 'https:') {
        cookieString = cookieString + '; Secure';
      }
      document.cookie = cookieString;
    }
  };

  window.GOVUK.getCookie = function (name) {
    var nameEQ = name + '=';
    var cookies = document.cookie.split(';');
    for (var i = 0, len = cookies.length; i < len; i++) {
      var cookie = cookies[i];
      while (cookie.charAt(0) === ' ') {
        cookie = cookie.substring(1, cookie.length);
      }
      if (cookie.indexOf(nameEQ) === 0) {
        return decodeURIComponent(cookie.substring(nameEQ.length));
      }
    }
    return null;
  };
}(window));