Uploading multiple files with paperclip - ruby-on-rails

Question

I am having problems uploading multiple files using paper clip,
my models are as such
slider has_many imgarrays
imgarrays has_many imageobjects
imageobjects have_attachment(as for paperclip)
I have no problems receiving a single image and saving it using paperclip on my other models, but i am not sure of how to handle the array returned by imgarrays param during a multiple file upload.
Here is my rails server logs:
Started POST "/slider" for 127.0.0.1 at 2012-07-23 10:14:17 +0800
Processing by SliderController#create as HTML
Parameters: {"utf8"=>"✓", "authenticity_token"=>"7HcHtSlOsU/bnxb9emhAsSl/GFBraIE6NxwijHl3REM=", "slider"=>{"question"=>"", "answer"=>"", "score"=>"", "industry_name"=>"",
"imgarrays"=>[#<ActionDispatch::Http::UploadedFile:0x007fb471e99f30 #original_filename="Icon.png", #content_type="image/png", #headers="Content-Disposition: form-data; name=\"slider[imgarrays][]\"; filename=\"Icon.png\"\r\nContent-Type: image/png\r\n", #tempfile=#<File:/var/folders/2s/n9wb5x4534nfs1cbrlph32v00000gp/T/RackMultipart20120723-53499-1lyi4yf>>, #<ActionDispatch::Http::UploadedFile:0x007fb471e99dc8 #original_filename="Icon#2x.png", #content_type="image/png", #headers="Content-Disposition: form-data; name=\"slider[imgarrays][]\"; filename=\"Icon#2x.png\"\r\nContent-Type: image/png\r\n", #tempfile=#<File:/var/folders/2s/n9wb5x4534nfs1cbrlph32v00000gp/T/RackMultipart20120723-53499-10lala2>>, #<ActionDispatch::Http::UploadedFile:0x007fb471e99d50 #original_filename="greenButton.png", #content_type="image/png", #headers="Content-Disposition: form-data; name=\"slider[imgarrays][]\"; filename=\"greenButton.png\"\r\nContent-Type: image/png\r\n", #tempfile=#<File:/var/folders/2s/n9wb5x4534nfs1cbrlph32v00000gp/T/RackMultipart20120723-53499-or2rdk>>]}, "commit"=>"Create!"}
Completed 500 Internal Server Error in 18ms
ActiveRecord::AssociationTypeMismatch (Imgarray(#70206507050500) expected, got ActionDispatch::Http::UploadedFile(#70206487229960)):
app/controllers/slider_controller.rb:12:in `new'
app/controllers/slider_controller.rb:12:in `create'
Rendered /Users/Kinnovate/.rvm/gems/ruby-1.9.3-p194/gems/actionpack-3.1.1/lib/action_dispatch/middleware/templates/rescues/_trace.erb (1.4ms)
Rendered /Users/Kinnovate/.rvm/gems/ruby-1.9.3-p194/gems/actionpack-3.1.1/lib/action_dispatch/middleware/templates/rescues/_request_and_response.erb (1.4ms)
Rendered /Users/Kinnovate/.rvm/gems/ruby-1.9.3-p194/gems/actionpack-3.1.1/lib/action_dispatch/middleware/templates/rescues/diagnostics.erb within rescues/layout (6.5ms)
new.html.erb for slider
<div>
<%= form_for #slider ,:url=>"/slider" , :html => { :multipart => true } do |f| %>
<%= f.label :question , "question"%>
<%= f.text_field :question %> </br>
<%= f.label :answer , "answer array (comma seperated)"%>
<%= f.text_field :answer %> </br>
<%= f.label :score , "score"%>
<%= f.text_field :score %> </br>
<%= f.label :industry_name , "industry"%>
<%= f.text_field :industry_name %> </br>
<%= f.label :attachedimg , "image"%>
<%= f.file_field :imgarrays, :multiple =>:true %> </br>
<%= f.submit "Create", class: "btn btn-large btn-primary" %>
<% end %>
</div>
<%= link_to 'Cancel', slider_index_path %>

Answer 1

Here is my code that worked well to upload multiple file using paperclip:
We can achieve using nested attributes or using normal easy method.
The following code shows normal method:
User.rb
has_many :images, :dependent => :destroy
Image.rb
has_attached_file :avatar, :styles => { :medium => "300x300>" }
belongs_to :user
users/views/new.html.erb
<%= form_for #user, :html => { :multipart => true } do |f| %>
......
....
<%= file_field_tag :avatar, multiple: true %>
<% end %>
Users_controller:
.....
if #user.save
# params[:avatar] will be an array.
# you can check total number of photos selected using params[:avatar].count
params[:avatar].each do |picture|
#user.images.create(:avatar=> picture)
# Don't forget to mention :avatar(field name)
end
end
Thats it. images got uploaded, this may not be the good way but it works.