Posted by
flyerhzm
on
August 23, 2010
I don't remember how many times I need to fetch current user in models, such as audit log. Here is a flexible way to set the current user in and fetch the current user from User model.
I don't remember how many times I need to fetch the current user in models, for example, I want to log who creates, updates or destroys a post in the Audit model. There is no default way to fetch the current user in models, current_user object is always assigned in controllers (thanks to authentication plugins, restful_authentication, authlogic and devise), we can pass the current user object from controllers to models, but it is too ugly. I think the better way is to add the current user to User model by Thread.current hash.
class User < ActiveRecord::Base
def self.current
Thread.current[:user]
end
def self.current=(user)
Thread.current[:user] = user
end
end
As you seen, we add two class methods to User model, User.current to fetch the current user and User.current= to assign the current user. So what you need to do is to assign the current user in User model every request you need a current user. Such as
class ApplicationController < ActionController::Base
def set_current_user
User.current = current_user
end
end
class PostsController < ApplicationController
before_filter :require_user # require_user will set the current_user in controllers
before_filter :set_current_user
end
Now you can easily fetch the current_user in models by User.current, enjoy it!
Comments
current_user.posts.create params[:post]to create a Post that has the current user attached. But for more complex models and observers it might be necessary for them to know the current user to carry out their operations. Having User.current as a defined API for determining the current user (and then in the case of a web-app set that variable on each request) seems like a reasonable approach.