require 'rack/utils'
require 'rack/request'
require 'action_dispatch/middleware/cookies'
require 'active_support/core_ext/object/blank'
module ActionDispatch
module Session
class SessionRestoreError < StandardError #:nodoc:
end
class AbstractStore
ENV_SESSION_KEY = 'rack.session'.freeze
ENV_SESSION_OPTIONS_KEY = 'rack.session.options'.freeze
class SessionHash < Hash
def initialize(by, env)
super()
@by = by
@env = env
@loaded = false
end
def [](key)
load! unless @loaded
super(key.to_s)
end
def []=(key, value)
load! unless @loaded
super(key.to_s, value)
end
def to_hash
h = {}.replace(self)
h.delete_if { |k,v| v.nil? }
h
end
def update(hash)
load! unless @loaded
super(hash.stringify_keys)
end
def delete(key)
load! unless @loaded
super(key.to_s)
end
def inspect
load! unless @loaded
super
end
def loaded?
@loaded
end
private
def load!
stale_session_check! do
id, session = @by.send(:load_session, @env)
(@env[ENV_SESSION_OPTIONS_KEY] ||= {})[:id] = id
replace(session.stringify_keys)
@loaded = true
end
end
def stale_session_check!
yield
rescue ArgumentError => argument_error
if argument_error.message =~ %r{undefined class/module ([\w:]*\w)}
begin
# Note that the regexp does not allow $1 to end with a ':'
$1.constantize
rescue LoadError, NameError => const_error
raise ActionDispatch::Session::SessionRestoreError, "Session contains objects whose class definition isn't available.\nRemember to require the classes for all objects kept in the session.\n(Original exception: #{const_error.message} [#{const_error.class}])\n"
end
retry
else
raise
end
end
end
DEFAULT_OPTIONS = {
:key => '_session_id',
:path => '/',
:domain => nil,
:expire_after => nil,
:secure => false,
:httponly => true,
:cookie_only => true
}
def initialize(app, options = {})
@app = app
@default_options = DEFAULT_OPTIONS.merge(options)
@key = @default_options.delete(:key).freeze
@cookie_only = @default_options.delete(:cookie_only)
ensure_session_key!
end
def call(env)
prepare!(env)
response = @app.call(env)
session_data = env[ENV_SESSION_KEY]
options = env[ENV_SESSION_OPTIONS_KEY]
if !session_data.is_a?(AbstractStore::SessionHash) || session_data.send(:loaded?) || options[:expire_after]
session_data.send(:load!) if session_data.is_a?(AbstractStore::SessionHash) && !session_data.send(:loaded?)
sid = options[:id] || generate_sid
session_data = session_data.to_hash
value = set_session(env, sid, session_data)
return response unless value
cookie = { :value => value }
unless options[:expire_after].nil?
cookie[:expires] = Time.now + options.delete(:expire_after)
end
if options[:domain] == :all
top_level_domain = env["HTTP_HOST"].split('.')[-2..-1].join('.')
options[:domain] = ".#{top_level_domain}"
end
request = ActionDispatch::Request.new(env)
set_cookie(request, cookie.merge!(options))
end
response
end
private
def prepare!(env)
env[ENV_SESSION_KEY] = SessionHash.new(self, env)
env[ENV_SESSION_OPTIONS_KEY] = @default_options.dup
end
def generate_sid
ActiveSupport::SecureRandom.hex(16)
end
def set_cookie(request, options)
request.cookie_jar[@key] = options
end
def load_session(env)
request = Rack::Request.new(env)
sid = request.cookies[@key]
sid ||= request.params[@key] unless @cookie_only
sid, session = get_session(env, sid)
[sid, session]
end
def ensure_session_key!
if @key.blank?
raise ArgumentError, 'A key is required to write a ' +
'cookie containing the session data. Use ' +
'config.session_store SESSION_STORE, { :key => ' +
'"_myapp_session" } in config/application.rb'
end
end
def get_session(env, sid)
raise '#get_session needs to be implemented.'
end
def set_session(env, sid, session_data)
raise '#set_session needs to be implemented and should return ' <<
'the value to be stored in the cookie (usually the sid)'
end
end
end
end