Nested attributes using paperclip rails 4 - ruby-on-rails-4

Question

I am new to rails and I am trying to work with nested attributes.
The main idea is to have a a deal(offer) model, a deal will have multiple deal_photos from paperclip.
I have already watched Ryan's Railscast for nested forms and read many articles with many tips regarding problems on the same issue but still it doesn't work for me.
Here is my Implementation:
class Deal < ActiveRecord::Base
belongs_to :user
has_many :deal_photos, dependent: :destroy
accepts_nested_attributes_for :deal_photos
end
class DealPhoto < ActiveRecord::Base
belongs_to :deal
has_attached_file :photo, :styles => { :large => "600x170", :medium => "250x250!", :thumb => "100x100>" }, :default_url => lambda { |photo| photo.instance.set_default_url}
def set_default_url
ActionController::Base.helpers.asset_path('missing.png')
end
end
In my deals controller:
class DealsController < ApplicationController
def new_deal
#deal=Deal.new()
#user= User.find(params[:id])
3.times { #deal.deal_photos.build }
end
def create
#deal = Deal.new(deal_param)
#user= User.find(params[:user_id])
if #deal.save
#user.deals << #deal
flash[:notice]="Thank you"
end
end
def edit
#deal=Deal.find(params[:deal_id])
3.times { #deal.deal_photos.build }
end
def update
#deal=Deal.find(params[:id])
if #deal.update_attributes(deal_params)
flash[:notice]="Deal updated successfully"
end
end
private
def deal_params
params.require(:deal).permit(:title, :description, :contact_num, :user_id, :deal_photos_attributes => [ :id, :caption, :photo, :deal_id])
end
Finally in my form for a new deal:
<%= form_for(:deal, :url=>{:action=>'create', :user_id=> #user.id}) do |f| %>
<label>Title<b style="color:red;">*</b>
<%= f.text_field(:title, :placeholder=>"") %>
</label>
------------more fields---------------------
<%= f.fields_for :deal_photos do |builder| %>
<div>
<%= builder.label :caption, "Image Caption" %>
<%= builder.text_field :caption %>
<%= builder.label :photo, "Image File" %>
<%= builder.file_field :photo %>
</div>
<%end%>
<%= button_tag("Create", :class=> "secondary button", :button_type => "submit") %>
(I have migrated the db for deals_photo to accept paperclip)
The above, creates a form with all fields but instead of 3 inputs for file upload shows only one. It creates 3 empty associations #deal.deal_photos but even if I choose one image to upload from the form it doesn't save it.
If you have any useful advices or another similar question please help!

Answer 1

What's in your deal_param method?
Do you permit deal_photos' attributes in it?
If no then do something like
def deal_params
params.require(:deal).permit(deal_attr1, deal_attr2,...., deal_photos_attributes: [:deal_photo_attr1, ...])
end
Also, do you get a deal_id in your deal_photos in view?

Answer 2

Finally, I was able to solve the problem in the new_deal.html.erb when I replaced the:
<%= form_for(:deal, :url=>{:action=>'create', :user_id=> #user.id}) do |f| %>
with
<%= form_for(#deal, :url=>{:action=>'create', :user_id=> #user.id}) do |f| %>
What is changed is that the second line is for the specific new deal instance. Maybe the reason that the first was not working is that the deal_photos didn't get the deal_id, as Alexphys said. But still I haven't figure out the exact reason.