Question

I’ve been stuck for a while trying to add tags to posts.
I’m using http://railscasts.com/episodes/258-token-fields as guide.

Post form has nested images and tags.
Tags are handled as authors in Ryan’s episode.

When creating new post, I’m getting, stack level too deep, error.

Any ideas?

Model

class Post < ActiveRecord::Base
  attr_accessible :title, :body, :keywords, :description, :post_images_attributes, :tags

  has_and_belongs_to_many :tags
  has_many :post_images, :dependent => :destroy

  validates :title, :presence => true
  validates :body, :presence => true
  validates :keywords, :presence => true
  validates :description, :presence => true

  extend FriendlyId
  friendly_id :title, use: :slugged

  accepts_nested_attributes_for :post_images, :allow_destroy => true #, :reject_if => lambda { |a| a[:image].blank? }
  accepts_nested_attributes_for :tags, :allow_destroy => true

  attr_reader :tags

  def tags=(ids)
    self.tags = ids.split(",")
  end
end

Form

<%= form_for @post, :html => {:multipart => true} do |f| %>
  <div class="field">
    <%= f.label :title %><br/>
    <%= f.text_field :title %>
  </div>
  <div class="field">
    <%= f.label :body %><br/>
    <%= f.text_area :body %>
  </div>
  <div class="field">
    <%= f.label :keywords %><br/>
    <%= f.text_field :keywords %>
  </div>
  <div class="field">
    <%= f.label :description %><br/>
    <%= f.text_field :description %>
  </div>

  <div class="field">
    <%= f.label :tags %><br/>
    <% if !@post.tags.blank? %>
      <%= f.text_field :tags, "data-pre" => @post.tags.map(&:attributes).to_json %>
    <% else %>
      <%= f.text_field :tags %>
    <% end %>
  </div>

  <%= f.fields_for :post_images do |builder| %>
    <%= render "post_image_fields", :f => builder %>
  <% end %>
  <p><%= link_to_add_fields "Add Image", f, :post_images %></p>

  <div class="actions">
    <%= f.submit %>
  </div>
<% end %>

Log

Started POST "/posts" for 127.0.0.1 at 2012-03-29 15:43:57 +0200
  Processing by PostsController#create as HTML
  Parameters: {"utf8"=>"✓", "authenticity_token"=>"r/oWrpb4AOAwMrp+G6vOUmaQPFh32
NsabUa2h+O5KrY=", "post"=>{"title"=>"Test post", "body"=>"Test body", "keywords"
=>"key, words", "description"=>"description", "tags"=>"1", "post_images_attribut
es"=>{"0"=>{"image"=>#<ActionDispatch::Http::UploadedFile:0x392e410 @original_fi
lename="africa-web-l.jpg", @content_type="image/jpeg", @headers="Content-Disposi
tion: form-data; name=\"post[post_images_attributes][0][image]\"; filename=\"afr
ica-web-l.jpg\"\r\nContent-Type: image/jpeg\r\n", @tempfile=#<File:C:/Users/user
/AppData/Local/Temp/RackMultipart20120329-5772-dl0ix3>>, "is_main"=>"1", "_destr
oy"=>"false"}}}, "commit"=>"Create Post"}
Completed 500 Internal Server Error in 24ms

SystemStackError (stack level too deep):

Answer 1

Stack level too deep means that you are recursively changing an attribute. It happens here:

def tags=(ids)
  self.tags = ids.split(",")
end

You need to use different name for this method.