/cookie-consent

🍪 Standalone script to display a cookie consent to comply with EU cookie law

Primary LanguageJavaScript

Cookie Consent

🍪 Standalone script to display a cookie consent to comply with EU cookie law.

Yet another cookie consent bar… Whyyyyy❓❓

…Well, most of the popular existing solutions have issues like…

  • require loading the JavaScript through a CDN → which may track visitors and therefore signifies a privacy issue
  • require a JavaScript framework like jQuery → which may not exist if the current site only adds a cookie because of one tracking tool
  • add advertisements
  • add trackers
  • are hard to modify
  • set inline styles → don't allow separating scripts & styles, which makes it harder to add custom stylesheets
  • have to many styles or no styles at all
  • hardcode labels/text in the JavaScript → limit translations & text changes
  • don't have an easy way to wrap dependent scripts
  • are too big/complex (mostly because styles, scripts & labels are mixed, and the options to change all of them are more complex than the cookie logic itself)

Goals of this library:

  • KISS
  • Separate JavaScript logic, CSS styles and HTML markup
  • Allow to copy/integrate a small, single JavaScript (no CDN, no framework)
  • Allow to change text/labels as desired (e.g. in application)
  • Add basic fallbacks (e.g. styles), which may be overwritten/removed/extended
  • Allow to gain different types of consent
  • Don't make any external requests
  • Don't manage multiple cookie sources (use a cookie consent manager instead)
  • Expose plain conditions for other JavaScripts depending on provided consent

Requirements

  • JavaScript
  • Internet Explorer > 10, Edge > 12, Safari > 10, Opera > 49, Firefox > 48, Chrome > 57

Demo

🚀 https://pixelbrackets.gitlab.io/cookie-consent/

Preliminary considerations

đź“š Please read this section as a prerequisite prior to installing the script.

The most obvious reason for the EU cookie law is to inform the user about cookie usage. But even more important is the constraint for website operators to think about cookie usage. They should ask themselves how intrusive a cookie is, what data does each cookie hold, is its lifespan appropriate to its purpose, is it a first or third‑party cookie, who controls the data?

Instead of saying “we use all kinds of cookies, I don't even know which and why” a website owner should be able to tell why and when cookies are used.

A website needs to differentiate…

  • between first-party and third-party cookies,
  • between session and persistent cookies and
  • between necessary and non-necessary cookies.

A cookie is »necessary« if it is required by the service for the sole purpose of communication and storing stateful data. A first-party cookie which stores a login state or items in a shopping cart and is limited to a session only (erased when the user closes the browser), may be necessary.

👉 Not all cookies require a consent, see European Commission - Internet Handbook.

  • First‑party session cookies DO NOT require informed consent.
  • First‑party persistent cookies DO require informed consent.
  • Third‑party session and persistent cookies DO require informed consent.
Origin Duration Requires consent
First‑party Session ❌
First‑party Persistent ✔ (except »necessary« cookies limited to a few hours, like shopping carts)
Third‑party Session ✔
Third‑party Persistent ✔

Although not mandatory it may be helpful to further differentiate between different usage types of cookies.

  • Necessary cookies = storing stateful data, like a shopping cart or a login status
  • Experience cookies = user preferences, like data previously entered into forms
  • Analytical cookies = target user behaviour, like how often an item was clicked

When this script was first created, there were still different views on how to gain consent from a user.

  • Agreement due to continued usage → Only inform the user about cookie usage and that the website will continue to do so if the user continues to use the website.
  • Opt-Out → Inform the user about cookie usage, but let the user disagree to usage of cookies with a click on a button. After that existing cookies (except the denied consent) are removed and now new cookies created anymore.
  • Opt-In → User agrees to usage of cookies with a click on a button, until then no non-necessary cookies are stored.

🌪️ However, please note that since 2020 only an opt-in is a permissible form of consent to cookies within the EU! Users must actively consent, preset checkboxes or opt-outs are no longer permitted.

Other regions, like the US, have different legal requirements. Consent due to continued usage is therefore still supported in this script, but should no longer be used within the EU.

The cookie consent bar should link to a page informing about cookie usage (eg. privacy notes)…

  • in plain, jargon‑free language
  • why cookies are used (to remember user actions, identify users etc.)
  • types of used cookies (e.g. session or permanent, first or third‑party)
  • who controls/accesses the cookie‑related information (first or third‑party)
  • how users can withdraw consent (e.g. close browser, clear cache, opt-out button)

The different origins, usage types and ways to gain consent are considered in this repository. It uses »levels« for this, see sections »Usage & Levels«.

Installation

Packagist https://packagist.org/packages/pixelbrackets/cookie-consent

Usage

The most important script of this package is cookie-consent.js, which handles the consent. Everything else is optional. The script looks for certain data attributes in elements with a certain class name. If everything is missing, then it will set default values instead.

The script stores what type of consent was given by the user and how long it is supposed to be valid. The consent is categorised into different »levels«. Read more about these levels in the following chapter.

All your own scripts, which want to write cookies or execute actions requiring consent, must read the stored consent level to continue or cancel.

Integration

đź”° Take a look at the demo.html file, which holds all example files.

Set up consent bar

  • Copy the cookie consent bar HTML and integrate it into your own view
    • Change the labels/text as you want, but try to keep the markup structure
    • Add a link to a separate privacy page
    • See the »configuration« section to learn how to change the default values for consent levels and duration
  • Integrate cookie.js and cookie-consent.js into your own view
    • Maybe concat and minify the files according to your own asset structure
  • Either copy the default stylesheet cookie-consent.css or write your own, styles are independent of the script
  • The consent level is stored in a cookie called »cookie-consent«

Guard clause your own scripts

  • Adapt all scripts with cookie actions to read the given consent level from cookie-consent
    • The example file tracker.js shows how to react to the level in JavaScript 
      if ($.cookie('cookie-consent') !== null && $.cookie('cookie-consent') >= 50) {
  /* Consent level 50 given, trigger action */
}

Optional: Add your own consent events

  • Write your own actions to change the level stored in cookie cookie-consent
    • The example file tracker.js shows how to set the level with inline JavaScript 
      <button type="button" class="btn btn-secondary" onClick="$.cookie('cookie-consent', 80, 720); return false;">Accept all cookies</button>

Levels

The given consent is categorised into different »levels«. They are triggered by different events, like continued usage of the website or a button click (Opt-In).

All other scripts need to ask for the current level to check whether they are allowed to write a cookie or not.

These behaviours are intended for the following levels:

Set Level 〽️ Triggered by Cookie Bar Visibillity Cookie Types Allowed Notes
null Browser blocks cookies Dont show None Website may not work
0 Opt-Out Dont show First Party, Session, Necessary cookies
1 Agreement due to continued usage Keep showing First Party, Session, Necessary cookies
10 Agreement due to continued usage Keep showing First-Party, Persistent, Experience
20 Agreement due to continued usage Keep showing First-Party, Persistent, Analytical
30 Agreement due to continued usage Keep showing Third-Party, Session, Experience
40 Agreement due to continued usage Keep showing Third-Party, Persistent, Analytical
50 Opt-In Dont Show First-Party, Persistent, Experience Missing necessary cookies here? See level 0
60 Opt-In Dont Show First-Party, Persistent, Analytical
70 Opt-In Dont Show Third-Party, Session, Experience
80 Opt-In Dont Show Third-Party, Persistent, Analytical “Allow all cookies”

🏔️ You may define your own values between these levels or above level 80.

Examples

In relation to the table above, the following use cases may require these levels:

  • Internal shopping cart → no consent required (you may check for level 1 or ignore it)
  • Internal form wizard (persist user input), shall be allowed by continued usage → requires at least level 10
  • Internal tracking tool, shall be allowed by continued usage → requires at least level 20
  • Internal tracking tool, shall be allowed by Opt-In only → requires at least level 50
  • External form wizard (keep user input in session only), shall be allowed by continued usage → requires at least level 30
  • External tracking tool, shall be allowed by continued usage → requires at least level 30
  • External tracking tool, shall be allowed by Opt-In only → requires at least level 80

⚠️Example use cases, your use cases and internal requirements may differ.

Configuration

To let the script set and use different levels it is possible to configure which event triggers what consent level and how long this level is valid.

To do so the attributes data-level and data-duration may be set on two different places.

Triggered by continued usage

  • Level of cookie consent set by agreement due to continued usage
    • Set in data-level attribute of .cookie-consent Element (DIV)
    • Integer, levels as defined in the »levels« table above
    • Default value »1«, usually »20«, always lower than »50«
  • Duration of cookie consent set by agreement due to continued usage
    • Set in data-duration attribute of .cookie-consent Element (DIV)
    • Integer, duration in hours
    • Default value »8«, usually »8«, never greater than »8760« (365 days)

Triggered by Opt-In

  • Level of cookie consent set by opt-in due to button click
    • Set in data-level attribute of .cookie-accept Element (BUTTON)
    • Integer, levels as defined in the »levels« table above
    • Default value »50«, usually »80«
  • Duration of cookie consent set by opt-in due to button click
    • Set in data-duration attribute of .cookie-accept Element (BUTTON)
    • Integer, duration in hours
    • Default value »8«, usually »8760«, never greater than »8760« (365 days)
  • Note: You may set up multiple opt-in buttons, all they need is a .cookie-accept class and the desired data attributes

âť• If the default values are sufficient for your app, you even can omit the data-* attributes.

đź”° Again, take a look at the demo.html file to try out different examples.

Source

https://gitlab.com/pixelbrackets/cookie-consent

License

GNU General Public License version 2 or later

The GNU General Public License can be found at http://www.gnu.org/copyleft/gpl.html.

Author

Dan Kleine (Dan Untenzu) (mail@pixelbrackets.de / @pixelbrackets)

Changelog

See CHANGELOG.md

Contribution

This script is Open Source, so please use, share, patch, extend or fork it.