Question

I’m a struggling newbie to programming and trying to make a freemium style app with multiple plans available.

I’m using the cancan gem to assign venues a role depending on what plan they are on (free, premium, premium+).

I know how I can limit certain options being displayed in the views depending on which plan is assigned but how can I go about limiting number of records added to a venue depending on which plan is assigned?

e.g.

• I would like all venues to have photos but the free venues should be
  limited to just 3.
• I would also like all venues to have searchable tags but have the number of tags allowed change depending on which plan the venue is on.

Currently the plans are just specified in the venue model as:

PLANS = %w[free premium premium+]

edit

Thanks to the answer from Alex Peattie I think I’m on the right track now.

I changed the line validate_on_create :photo_count_within_limit to:

validate :venuephoto_count_within_limit, :on => :create

but am getting a ArgumentError in VenuesController#update: comparison of Fixnum with nil failed error.

another edit

So all is now well, just made these changes:

def photo_limit
  {:free => 3, :premium => 10}[plan.to_sym]
end

and

validate :venuephoto_count_within_limit, :on => :create

Thanks for any help its much appreciated!

Answer 1

I’d give the Venue model methods for photo_limit, tag_limit etc.

class Venue < ActiveRecord::Base

  def photo_limit
    {:free => 3, :premium => 20, :"premium+" => 999}[plan]
  end

end

(this assumes a .plan method which will return the current Venue’s plan)

Then use validations in Photo, like so:

class Photos < ActiveRecord::Base

  belong_to :venue
  validate_on_create :photo_count_within_limit

  def photo_count_within_limit
    if self.venue.photos(:reload).count >= self.venue.photo_limit
      errors.add(:base, "Exceeded venue photo limit")
    end
  end

end