ccs-digitalmarketplace-govuk-frontend/digitalmarketplace/helpers/cookie/cookie-functions.js

Digital Marketplace GOV.UK Frontend contains the code you need to start building a user interface for Digital Marketplace.

import Cookies from 'js-cookie'

// used by the cookie banner component
const DEFAULT_COOKIE_CONSENT = {
  analytics: false
}

const COOKIE_CATEGORIES = {
  _ga: 'analytics',
  _gid: 'analytics',
  _gat_govuk_shared: 'analytics'
}

const DOMAINS = [
  '.digitalmarketplace.service.gov.uk',
  'www.applytosupply.digitalmarketplace.service.gov.uk'
]

const cookiesAPI = Cookies.withAttributes({ path: '/' })

const COOKIE_SETTINGS_COOKIE_NAME = 'dm_cookies_policy'

export function getConsentCookie () {
  const consentCookie = cookiesAPI.get(COOKIE_SETTINGS_COOKIE_NAME)
  let 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
}

export function setConsentCookie (options) {
  let cookieConsent = getConsentCookie()

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

  for (const cookieType in options) {
    cookieConsent[cookieType] = options[cookieType]
    // Delete cookies of that type if consent being set to false
    if (!options[cookieType]) {
      const cookiePrefixes = []

      Object.entries(COOKIE_CATEGORIES).forEach(([cookieName, cookieCategory]) => {
        if (cookieCategory === cookieType) {
          cookiePrefixes.push(cookieName)
        }
      })

      const cookieList = Object.keys(cookiesAPI.get()).filter((cookieName) => cookiePrefixes.some((cookiePrefix) => cookieName.startsWith(cookiePrefix)))

      for (const cookie of cookieList) {
        DOMAINS.forEach((domain) => cookiesAPI.remove(cookie, { domain: domain }))
        cookiesAPI.remove(cookie, { domain: window.location.hostname.replace(/^www\./, '.') })
      }
    }
  }

  setCookie(COOKIE_SETTINGS_COOKIE_NAME, JSON.stringify(cookieConsent), { days: 365 })
}

function checkConsentCookieCategory (cookieName, cookieCategory) {
  let currentConsentCookie = 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 = 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
  }
}

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

  if (COOKIE_CATEGORIES[cookieName]) {
    const cookieCategory = COOKIE_CATEGORIES[cookieName]

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

// Usage :
// Setting a cookie:
// Cookie('hobnob', 'tasty', { days: 30 })

export function setCookie (name, value, options) {
  if (checkConsentCookie(name, value)) {
    const cookieOptions = {}
    if (typeof options === 'undefined') {
      options = {}
    }
    if (options.days) {
      const date = new Date()
      date.setTime(date.getTime() + (options.days * 24 * 60 * 60 * 1000))
      cookieOptions.expires = date
    }
    if (document.location.protocol === 'https:') {
      cookieOptions.secure = true
    }
    cookiesAPI.set(
      name,
      value,
      cookieOptions
    )
  }
}