RoR Catch Exception on Application Level

Question

For a specific role (group of users) I added the :readonly to every find on the active record

  def self.find(*args)
     if User.current_user.has_role? 'i_can_only_read'
        with_scope({:find => {:readonly => true}}) do
           result = super *args
        end
     end
  end

Of course it raises now ActiveRecord::ReadOnlyRecord Exceptions in Controller passed on to the user; not very nice.

Can I catch this type of error in one place? Like in production.rb or in the application.rb? Or can I configure a specific error page for this error?

Answer 1

Yes, simply override rescue_action_in_public like this:

class ApplicationController < ActionController::Base
...

  def rescue_action_in_public(exception)
    case exception
      when ActiveRecord::ReadOnlyRecord
        # DO SOME LOGIC HERE
      end
    end
  end
end

This will execute your action when in "production", but leave you with an informative stack trace when you are in "development".

Rails has a number of other rescue_action_* methods that might be more suitable to your problem...take a look at http://api.rubyonrails.org/classes/ActionController/Rescue.html