class ActionDispatch::Cookies

Read and write data to cookies through ActionController#cookies.

When reading cookie data, the data is read from the HTTP request header, Cookie. When writing cookie data, the data is sent out in the HTTP response header, Set-Cookie.

Examples of writing:

# Sets a simple session cookie.
# This cookie will be deleted when the user's browser is closed.
cookies[:user_name] = "david"

# Cookie values are String based. Other data types need to be serialized.
cookies[:lat_lon] = JSON.generate([47.68, -122.37])

# Sets a cookie that expires in 1 hour.
cookies[:login] = { value: "XJ-122", expires: 1.hour }

# Sets a cookie that expires at a specific time.
cookies[:login] = { value: "XJ-122", expires: Time.utc(2020, 10, 15, 5) }

# Sets a signed cookie, which prevents users from tampering with its value.
# It can be read using the signed method `cookies.signed[:name]`
cookies.signed[:user_id] = current_user.id

# Sets an encrypted cookie value before sending it to the client which
# prevent users from reading and tampering with its value.
# It can be read using the encrypted method `cookies.encrypted[:name]`
cookies.encrypted[:discount] = 45

# Sets a "permanent" cookie (which expires in 20 years from now).
cookies.permanent[:login] = "XJ-122"

# You can also chain these methods:
cookies.signed.permanent[:login] = "XJ-122"

Examples of reading:

cookies[:user_name]           # => "david"
cookies.size                  # => 2
JSON.parse(cookies[:lat_lon]) # => [47.68, -122.37]
cookies.signed[:login]        # => "XJ-122"
cookies.encrypted[:discount]  # => 45

Example for deleting:

cookies.delete :user_name

Please note that if you specify a :domain when setting a cookie, you must also specify the domain when deleting the cookie:

cookies[:name] = {
  value: 'a yummy cookie',
  expires: 1.year,
  domain: 'domain.com'
}

cookies.delete(:name, domain: 'domain.com')

The option symbols for setting cookies are:

Constants

COOKIES_DIGEST
COOKIES_ROTATIONS
COOKIES_SAME_SITE_PROTECTION
COOKIES_SERIALIZER
CookieOverflow

Raised when storing more than 4K of session data.

GENERATOR_KEY
HTTP_HEADER

Cookies can typically store 4096 bytes.

SECRET_KEY_BASE
USE_COOKIES_WITH_METADATA

Public Class Methods

new(app) click to toggle source
# File lib/action_dispatch/middleware/cookies.rb, line 690
def initialize(app)
  @app = app
end

Public Instance Methods

call(env) click to toggle source
# File lib/action_dispatch/middleware/cookies.rb, line 694
def call(env)
  request = ActionDispatch::Request.new env

  status, headers, body = @app.call(env)

  if request.have_cookie_jar?
    cookie_jar = request.cookie_jar
    unless cookie_jar.committed?
      cookie_jar.write(headers)
      if headers[HTTP_HEADER].respond_to?(:join)
        headers[HTTP_HEADER] = headers[HTTP_HEADER].join("\n")
      end
    end
  end

  [status, headers, body]
end