Rails: Access to Current_User from Within a Model in Ruby on Rails

Rails: Access to current_user from within a model in Ruby on Rails

I'd say your instincts to keep current_user out of the model are correct.

Like Daniel I'm all for skinny controllers and fat models, but there is also a clear division of responsibilities. The purpose of the controller is to manage the incoming request and session. The model should be able to answer the question "Can user x do y to this object?", but it's nonsensical for it to reference the current_user. What if you are in the console? What if it's a cron job running?

In many cases with the right permissions API in the model, this can be handled with one-line before_filters that apply to several actions. However if things are getting more complex you may want to implement a separate layer (possibly in lib/) that encapsulates the more complex authorization logic to prevent your controller from becoming bloated, and prevent your model from becoming too tightly coupled to the web request/response cycle.

ruby on rails - current_user on model

current_user is a devise helper to be used on Views and Controllers. If you have an instance method that needs the current_user you should probably move it's logic to a Controller.

It's better explained here: Access to current_user from within a model in Ruby on Rails

how access to helper current_user in model rails?

You can't (or, at the very least, you really really shouldn't).

Your models have no access at all to your currently instantiated controller. Your models are supposed to be designed in such a way that there might not even be a request or a user actually interacting interactively with the system (think ActiveJob).

You need to pass current_user into your model layer.

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Your specific problem is that you've invented something called helpers. That isn't a thing, it's nil, so you get your NoMethodError on nil:nilClass error. current_user is an instance method, so you would need to invoke it directly on an instance of your controller, not on the class itself.

Access Devise's current_user in Model

Essentially, this kind of logic doesn't belong in a Model, so you're best to pass current_user in through a function in the model or on creation. This answer sums it up.

I know, I know, that's not the answer you wanted. Unfortunately, it may be cleaner looking to you, but it adds overhead to your model that you really don't want.

current_user in Model

It's simple. Pass the current_user as an argument.

def tagged_users(current_user)
  # ...
end

And use it in the view.

 <% node.tagged_users(current_user)...

Alternatively, you can set an attr_accessor in the Node. But I would pass the user in.

class Node
  attr_accessor :current_user
end

Then, whenever you instant it's a node:

@node.current_user = current_user

How to access current_user object in model?

current_user is not available in any model, to access current_user in model do this

In your application controller

before_filter :set_current_user

def set_current_user
  Team.current_user = current_user
end

in your Team model add this line

cattr_accessor :current_user

Congrats, now current_user is available in every model, to get the current user just use the following line everywhere

Team.current_user

NOTE: Restart the server after adding the lines mentioned above!

Now in your question you can use it like

def set_default_url
  if Team.current_user.id == self.user_id
    "/assets/default_black_:style_logo.jpg"
  else
    "/assets/default_:style_logo.jpg"
  end
end

Hope this helps!

How to access to 'current_user' outside of controller and model

If the engine is running in the same thread then perhaps you could store the current_user in the Thread.

class ApplicationController < ActionController::Base

  around_action :store_current_user

  def store_current_user
    Thread.current[:current_user] = current_user
    yield
    ensure
    Thread.current[:current_user] = nil
  end

end

Then in your filter_comments.rb you can define a method

def current_user
  Thread.current[:current_user]
end

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