Paperclip url

[kostas vav]

I have a rails app that consists of a CMS system that I use in order to enter sights from a city to my database. I am using paperclip to upload images to amazon s3. All is working fine. Now I want my json files that an ios app will use to include the urls of the images uploaded in s3. I have seen some answers here but I cannot seem to make my code work. What I have is this..

place model

attr_accessible :assets_attributes, :asset
has_many :assets
accepts_nested_attributes_for :assets, :allow_destroy => true

asset model

class Asset < ActiveRecord::Base
  attr_accessible :asset_content_type, :asset_file_name, :asset_file_size, :asset_updated_at, :place_id, :asset
  belongs_to :place
  has_attached_file :asset

   validates_attachment :asset, :presence => true,
  :content_type => { :content_type => ['image/jpeg', 'image/png'] },
  :size => { :in => 0..1.megabytes }

end

view code

<%= f.fields_for :assets do |asset_fields| %>

<% if asset_fields.object.new_record? %>
<p>
    <%= asset_fields.file_field :asset %>
</p>
<% end %>

<% end %>
<br/>

<%= f.fields_for :assets do |asset_fields| %>

<% unless asset_fields.object.new_record? %>


<%= link_to image_tag(asset_fields.object.asset.url(:original), :class => "style_image"), (asset_fields.object.asset.url(:original)) %>
    <%= asset_fields.check_box :_destroy %>

<% end %>

<% end %>

places controller

def index
    @places = Place.all
    respond_to do |format|
      format.html # index.html.erb
      format.json { render json: @places }
    end
  end

Can anyone please help me?