Cookies are read and written through ActionController#cookies.
The cookies being read are the ones received along with the request, the cookies being written will be sent out with the response. Reading a cookie does not get the cookie object itself back, just the value it holds.
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.from_now }
# Sets a signed cookie, which prevents users from tampering with its value.
# The cookie is signed by your app's <tt>config.secret_key_base</tt> value.
# It can be read using the signed method <tt>cookies.signed[:name]</tt>
cookies.signed[:user_id] = current_user.id
# Sets a "permanent" cookie (which expires in 20 years from now).
cookies.permanent[:login] = "XJ-122"
# You can also chain these methods:
cookies.permanent.signed[: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"
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.from_now,
domain: 'domain.com'
}
cookies.delete(:name, domain: 'domain.com')
The option symbols for setting cookies are:
:value - The cookie's value.
:path - The path for which this cookie applies. Defaults to
the root of the application.
:domain - The domain for which this cookie applies so you can
restrict to the domain level. If you use a schema like www.example.com and want to share session
with user.example.com set :domain to :all. Make
sure to specify the :domain option with :all
again when deleting cookies.
domain: nil # Does not sets cookie domain. (default)
domain: :all # Allow the cookie for the top most level
domain and subdomains.
:expires - The time at which this cookie expires, as a Time
object.
:secure - Whether this cookie is only transmitted to HTTPS
servers. Default is false.
:httponly - Whether this cookie is accessible via scripting or
only HTTP. Defaults to false.
Raised when storing more than 4K of session data.
Cookies can typically store 4096 bytes.
# File lib/action_dispatch/middleware/cookies.rb, line 481 def initialize(app) @app = app end
# File lib/action_dispatch/middleware/cookies.rb, line 485 def call(env) status, headers, body = @app.call(env) if cookie_jar = env['action_dispatch.cookies'] cookie_jar.write(headers) if headers[HTTP_HEADER].respond_to?(:join) headers[HTTP_HEADER] = headers[HTTP_HEADER].join("\n") end end [status, headers, body] end