require 'foreman/thread_session'

#

# In several cases we want to break chain of responsibility in MVC a bit and provide

# a safe way to access current user (and maybe few more data items). Storing it as

# a global variable (or class member) is not thread-safe. Including ThreadSession::

# UserModel in models and ThreadSession::Controller in the application controller

# allows this without any concurrent issues.

#

# Idea taken from sentinent_user rails plugin.

#

# http://github.com/bokmann/sentient_user

# http://github.com/astrails/let_my_controller_go

# http://rails-bestpractices.com/posts/47-fetch-current-user-in-models

#

module Foreman

module ThreadSession

# module to be include in controller to clear the session data

# after (and evenutally before) the request processing.

# Without it we're risking inter-users interference.

module Cleaner

def self.included(base)

base.around_filter :clear_thread

end

def clear_thread

if Thread.current[:user] && !Rails.env.test?

Rails.logger.warn("Current user is set, but not expected. Clearing")

Thread.current[:user] = nil

end

yield

ensure

[:user, :organization, :location].each do |key|

Thread.current[key] = nil

end

end

end

# include this in the User model

module UserModel

def self.included(base)

base.class_eval do

def self.current

Thread.current[:user]

end

def self.current=(o)

unless o.nil? || o.is_a?(self)

raise(ArgumentError, "Unable to set current User, expected class '#{self}', got #{o.inspect}")

end

Rails.logger.debug "Setting current user thread-local variable to " + (o.is_a?(User) ? o.login : 'nil')

Thread.current[:user] = o

end

# Executes given block on behalf of a different user. Example:

#

# User.as :admin do

# ...

# end

#

# Use with care!

#

# @param [String] login to find from the database

# @param [block] block to execute

def self.as login

old_user = current

self.current = User.find_by_login(login)

yield if block_given?

ensure

self.current = old_user

end

end

end

end

# include this in the Organization model object

module OrganizationModel

def self.included(base)

base.class_eval do

def self.current

Thread.current[:organization]

end

def self.current=(organization)

unless organization.nil? || organization.is_a?(self)

raise(ArgumentError, "Unable to set current organization, expected class '#{self}', got #{organization.inspect}")

end

Rails.logger.debug "Setting current organization thread-local variable to #{organization || "none"}"

Thread.current[:organization] = organization

end

# Executes given block in the scope of an org:

#

# Organization.as_org organization do

# ...

# end

#

# @param [org]

# @param [block] block to execute

def self.as_org org

old_org = current

self.current = org

yield if block_given?

ensure

self.current = old_org

end

end

end

end

module LocationModel

def self.included(base)

base.class_eval do

def self.current

Thread.current[:location]

end

def self.current=(location)

unless location.nil? || location.is_a?(self)

raise(ArgumentError, "Unable to set current location, expected class '#{self}'. got #{location.inspect}")

end

Rails.logger.debug "Setting current location thread-local variable to #{location || "none"}"

Thread.current[:location] = location

end

# Executes given block without the scope of a location:

#

# Location.as_location location do

# ...

# end

#

# @param [location]

# @param [block] block to execute

def self.as_location location

old_location = current

self.current = location

yield if block_given?

ensure

self.current = old_location

end

end

end

end

end

end