Working with cookies

A cookie is a small piece of data that a website asks your browser to store on your computer or mobile device. The cookie allows the website to “remember” your actions or preferences over time.

Kentico provides an extensible framework, built around cookie levels, for manipulating cookies – from assigning specific levels of allowed cookies to users and contacts, to registering completely custom cookies and their corresponding cookie levels.

Setting the default cookie level

A site’s default cookie level determines which cookies the system stores in users’ browsers by default. To set the default cookie level:

1. Open Settings application and select the System category.
2. Under the Cookies heading, select a Default cookie level.
   • For an overview of individual cookie levels, see Cookie levels.
3. Click Save.

The system now uses the selected cookie level when evaluating which cookies should be stored in users’ browsers. 

Cookie levels

Kentico classifies cookies into several levels according to their purpose. The levels allow you to set cookie levels for users. The following are the default levels available in the cookie API (CMS.Helpers.CookieLevel class):

The numbers associated with each cookie level are integer constants, which allows you to further customize the granularity of available cookie levels. The levels ‘None’ and ‘All’ are set to an absolute value of 1000 to provide enough space for future Kentico updates or developer-specified custom levels.

For simplicity, there are 3 main levels, which represent the choices offered to visitors by the provided cookie web parts when asking for consent to use cookies:

Allowing users to choose their preferred cookie level on MVC sites

In compliance with the cookie law, you can allow users to select their preferred cookie level. Use the SetCurrentCookieLevel method provided by the ICurrentCookieLevelProvider service.

The following code snippets demonstrate the usage of the ICurrentCookieLevelProvider API on a basic example. The code allows users to set their preferred cookie level via a simple form.

using System.Web.Mvc;
using System.Collections.Generic;

using CMS.Helpers;

public class CookieLevelController : Controller
{
    private readonly ICurrentCookieLevelProvider cookieLevelService;

    // Initializes instances of required services using dependency injection
    public CookieLevelController(ICurrentCookieLevelProvider cookieLevelService)
    {
        this.cookieLevelService = cookieLevelService;
    }

    public ActionResult Index()
    {
        // Creates a list with the three default levels of cookie compliance relevant for site visitors.
        // The CookieLevel class is used to directly extract integer values corresponding to each cookie level
        // so that no additional mapping is necessary.
        var cookieLevels = new List<object>() {
                new { label = "Essential", value = CookieLevel.Essential },
                new { label = "Visitor", value = CookieLevel.Visitor },
                new { label = "All", value = CookieLevel.All }
            };

        return View(new SelectList(cookieLevels, "value", "label"));
    }

    // Sets the cookie level for the current user
    // The value passed into the action from the corresponding view directly corresponds to one of the system's 
    // cookie levels thanks to the CookieLevel class.
    [HttpPost]
    public ActionResult SetCookieLevel(int SelectedValue)
    {
        // Sets the cookie level for the current user to the level corresponding to the provided value
        cookieLevelService.SetCurrentCookieLevel(SelectedValue);

        return RedirectToAction(nameof(Index));
    }
}

The corresponding view contains a drop-down selectors that allows users to select the desired level of cookies.

@model SelectList

@using (Html.BeginForm("SetCookieLevel", "CookieLevel", FormMethod.Post))
{
    @Html.DropDownListFor(x => x.SelectedValue, Model)
    <input type="submit" value="Select" />
}