Question

This should be somewhat simple but cant seem to grasp the association.

I am using nested_form and paperclip. I have a model called photo to store all images and a post model. I am trying to show the photos associated to the relevant post but am getting ‘undefined method avatar’ when rendering the view.

class Post < ActiveRecord::Base
has_many :photos, :dependent => :destroy
accepts_nested_attributes_for :photos
attr_accessible :title, :comments, :photo_id, :avatar, :photos_attributes
end

Class Photo < ActiveRecord::Base
belongs_to :post
attr_accessible :avatar, :post_id
has_attached_file :avatar, :styles => { :medium => "300x300>", :thumb => "100x100>" }
end

Controller

def new
@post = Post.new
@post.photos.build
end

So i am under the impression that when a post gets built an association between the Post and Photo model is made? is that right?

So when i call this in the view i get the undefined method, can anyone advise where I am going wrong please

<% @posts.each do |f| %>
<ul>
 <li><%= f.title %></li>
 <li><%= f.department.name %></li>
 <li><%= image_tag f.avatar.url(:thumb) %></li>
 <li><%= link_to "Delete Post", post_path(f.id), :confirm => "Are you sure?", :method => :delete %></li>
</ul>
<% end %>

I have tried

<%= image_tag f.photo.avatar.url(:thumb) %>

but that doesnt work either

Answer 1

May be you are creating photo wrong.

Here you can see how the form looks: Nested form using paperclip

And also Post has_many :photos, so it must be somth. like

<% @posts.each do |f| %>
....


 <% f.photos.each do |photo| %>
   <%= image_tag photo.avatar.url(:thumb) %>
 <% end %>


...
<% end %>