Rails 4 Strong parameters : permit all attributes?

You can call the bang version of permit.

params.require(:user).permit!

Strong Params README on Github

Source code for reference:

def permit!
  each_pair do |key, value|
    convert_hashes_to_parameters(key, value)
    self[key].permit! if self[key].respond_to? :permit!
  end

  @permitted = true
  self
end

Skull0inc's answer works, but you might want to remove created_at and updated_at. The intention of strong params is to list only the attributes you want updatable by the controller. Something like...

def user_params
  params.require(:user).permit(User.column_names - ["created_at", "updated_at"])
end

Just in case someone need it for Rails 6, without even a model linked to your controller, you can use:

before_action :accept_all_params

private

def accept_all_params
  params.permit!
end

And done, now you can play with 🔥 as much as you want!