in rails how to limit users post count saved in database before asking to upgrade their account

Question

I'm adding a small way of controlling a non-subscribed user and a subscribed user. Basically my idea is that all users that sign up with the use of Devise, get an account. However, my model or the number of posts a user can have in the database stored based on user ID found should be 25 posts. I'm guessing the following would work;

Model

class Post
  belongs_to :user
  validate :quota, :on => :refresh

  def quota
     Posts = Posts.find(params[:id])
     if user.posts.count >= 25
        flash[:error] = "Sorry you need to upgrade"
     end
  end

end 

:refresh is something I'm working on where it grabs posts and adds these posts to the current_user within the database, or assigns the current_user id to each post it adds to the database.

am I correct on the above function? or should I add the validation count into my refresh controller/model like so;

class dashboard
   def refresh
      ...
      if self.user.posts.count >= 25
         flash[:error] = "You've reached maximum posts you can import"
      end
   end
end

Answer 1

I would use a before_filter on the corresponding controller(s):

class PostsController < ApplicationController
  before_filter :check_quota # you could add here: :only => [:index, :new]

  private # optionnal

  def check_quota
    if user.posts.count >= 25
      @quota_warning = "You've reached maximum posts you can import"
    end
  end
end 

And in the view(s):

<% if @quota_warning.present? %>
  <span><%= @quota_warning %></span>
<% end %>

Then add the validation on the model, to ensure the constraint:

class Post < ActiveRecord::Base
  belongs_to :user
  before_save :check_post_quota

  private # optionnal

  def check_post_quota
    if self.user.posts.count >= 25
      self.errors.add(:base, "You've reached maximum posts you can import")
      return false
    end
  end
end