Multiple images(Nested) not getting uploaded via paperclip in ruby on rails - ruby-on-rails

Question

I am developing a website in ruby on rails. I want to upload multiple images while creating post using paperclip. I could not find any images being uploaded into the public folder and hence images are not getting displayed when I create new post. I have created a model called Postimage.rb for images and referenced to already existing model "post".I have used paperclip to upload single image in other models and it is working fine.
rails g model postimage post:references caption:string
rails g paperclip post_images photo
Here is the Postimage.rb
class Postimage < ActiveRecord::Base
belongs_to :post
has_attached_file :photo,
:styles => {:small => "100x100>", :medium => "640x480>"}
validates_attachment_content_type :photo, :content_type => /\Aimage\/.*\Z/
end
And in the Post model,
class Post < ActiveRecord::Base
has_many :postimages
accepts_nested_attributes_for :postimages, :allow_destroy => true, :reject_if => lambda { |t| t[:postimage].nil? }
Here is the code in post controller
class PostsController < ApplicationController
before_action :set_post, only: [:show, :edit, :update, :destroy]
respond_to :html
def index
#posts = Post.all.order('created_at DESC').paginate(page: params[:page],:per_page =>7)
#users = User.all
respond_with(#posts)
end
def show
respond_with(#post)
end
def new
#post = Post.new
5.times {#post.postimages.build} # added this
respond_with(#post)
end
def edit
5.times{#post.postimages.build} # ... and this
end
def create
#post = current_user.posts.build(post_params)
#post.user_id = current_user.id
if #post.save
redirect_to #post, :notice =>"Post created successfully!!"
else
render "new"
end
end
def update
#post.update(post_params)
respond_with(#post)
end
def destroy
#post.destroy
redirect_to preschools_Home_path
#respond_with(#post)
end
private
def set_post
#post = Post.find(params[:id])
end
def post_params
params.require(:post).permit(:title, :content, postimages_attributes: [:caption, :photo])
end
Here is the code in _form.html in posts
<%= form_for(#post, :html =>{:multipart => true }) do |f| %>
<%=f.fields_for :postimages do |builder| %>
<%if builder.object.new_record? %>
<p>
<%= builder.label :caption, "Image Caption" %>
<%= builder.text_field :caption %>
</p>
<p>
<%= builder.label :photo, "Image File" %>
<%= builder.file_field :photo %>
</p>
<% end %>
<% end %>
<div class="actions">
<%= f.submit %>
</div>
<% end %>
Here is the code in show.html.erb in posts
<div>
<% #post.postimages.each do |postimage|%>
<%= image_tag (postimage.photo.url(:medium))%>
<% end %>
</div>
Can you please help me. Thanks.
I have added image column to post model. And that image is getting displayed. But in the case of multiple upload, it is not working.
Logs code below might help.
Parameters: {"utf8"=>"✓", "authenticity_token"=>"PHcPmsB+a0qy6tn4U/nRyycjGFYHiFuum7LNqO8EX24+mGq+Yu7Ct0Ls/odNyAjUtVkT1cMImYRYwnpVajQRXA==", "post"=>{"title"=>"1st post", "content"=>"Added image", "postimages_attributes"=>{"0"=>{"caption"=>"1st image", "photo"=>#<ActionDispatch::Http::UploadedFile:0x007f4a351b0ba8 #tempfile=#<Tempfile:/home/ubuntu/workspace/website/RackMultipart20150715-1790-7hfszv.jpg>, #original_filename="Murali.jpg", #content_type="image/jpeg", #headers="Content-Disposition: form-data; name=\"post[postimages_attributes][0][photo]\"; filename=\"Murali.jpg\"\r\nContent-Type: image/jpeg\r\n">}

Answer 1

The solution provided below works with Paperclip as well:
Rails 4 multiple image or file upload using carrierwave
Only difference would be in post_attachment.rb
Instead of:
class PostAttachment < ActiveRecord::Base
mount_uploader :avatar, AvatarUploader
belongs_to :post
end
You would have
class PostAttachment < ActiveRecord::Base
belongs_to :post
has_attached_file :avatar, styles: { medium: "300x300>", thumb: "100x100>" }, default_url: "/images/:style/missing.png"
validates_attachment_content_type :avatar, content_type: /\Aimage\/.*\Z/
end