Getting info from params into model rails paperclip app

Question

I have a rails app. I'm using gem:paperclip to upload photos to my server. What I'm trying to do is create a folder structure on the server using information from the perams hash. Please see code below.

photo controller.rb

 # POST /photos
 # POST /photos.json
 def create

 @photo = Photo.new(params[:photo])
 @photo.lat = params["photo%5Blat%5D"].to_s
 @photo.lng = params["photo%5Blng%5D"].to_s
 @photo.description = params[:description]
 @photo.takenby = params[:takenby].to_s

 @photo.save

 puts "photos/create photos.inspect= #{@photo.inspect}"



 end

photo.rb

 class Photo < ActiveRecord::Base


 attr_accessible :lat, :lng, :image
 vendor = params[:description]
 owner = params[:owner]
 Paperclip.interpolates :prefix  do |attachment, style|
 "#{owner}/#{Date.today.to_s }/#{vendor}"
 end


has_attached_file :image,
                :path => ":prefix/:basename.:extension",
                :styles => { :thumbnail => "57x57", :original => "100x100" },
                :storage => :s3,
                :s3_credentials => S3_CREDENTIALS

However, I'm getting this error on my server console.

 Started GET "/photos?lat=37.785834&lng=-122.406417" for 127.0.0.1 at 2012-09-26 
  21:08:57 -0700
 21:08:57 web.1  | Processing by PhotosController#index as JSON
 21:08:57 web.1  |   Parameters: {"lat"=>"37.785834", "lng"=>"-122.406417"}
 21:08:57 web.1  | Completed 500 Internal Server Error in 4ms
 21:08:57 web.1  | NameError (undefined local variable or method `params' for #<Class:0x007fb7d4fa3320>):
 21:08:57 web.1  |   app/models/photo.rb:23:in `<class:Photo>'
 21:08:57 web.1  |   app/models/photo.rb:18:in `<top (required)>'
 21:08:57 web.1  |   app/controllers/photos_controller.rb:14:in `index'

What do I need to change in the model so that paperclip saves the image on the server with the correct folder structure?

This solved my problem:

 photo.rb 

 Paperclip.interpolates :prefix  do |attachment, style|
 "#{attachment.instance.takenby}/#{Date.today.to_s }/#{attachment.instance.description}"
 end

But this introduced a new problem. I can't save different sized images anymore. How do I do that?

score 3 · Accepted Answer · edited May 23 '17 at 10:24

You can not access params hash in your class Photo by this way:

vendor = params[:description]
owner = params[:owner]

Example for description:

1) First, create a config/initializers/paperclip.rb file and add the following:

Paperclip.interpolates :description do |attachment, style|
  attachment.instance.description # or other attribute
end

2) Then,

has_attached_file :image,
                  :path => ":description/:basename.:extension",
                  :styles => { :thumbnail => "57x57", :original => "100x100" },
                  :storage => :s3,
                  :s3_credentials => S3_CREDENTIALS

3) Read this articles for more information:

score 0 · Answer 2 · answered Sep 27 '12 at 05:02

u cant access the params in the model directly. if u want to access them, u can pass the params as a parameter to a method thats declared in the model.

in controller, do

obj.set_values(params)

in model, do

def set_values(params)
  self.vendor = params[:description]
  self.owner = params[:owner] 
end

call the interpolation code before the model is saved.

score 0 · Answer 3 · answered Sep 27 '12 at 05:08

params is not accessible from your model, so those assignments will fail.

If vendor and owner are attributes for Photo, just assign them in the create action. You might want to modify your form so that all the values for the Photo model can be found in params[:photo] to cut down on the unnecessary assignments.

Uladz Kha · Answer 4 · 2012-09-27T08:20:50.337

$rails g paperclip post photo

$ rake db:migrate

go to Post.rb and add:

attr_accessible :photo has_attached_file :photo, :styles => { :small => '150x150', :normal => '400x400' }, :path => ":rails_root/public/system/:attachment/:id/:style/:filename", :url => "/system/:attachment/:id/:style/:filename"

open your _form.html.erb and rewrite is :

<%= form_for (@post) do |f| %>

to:

<%= form_for @post, :html => { :multipart => true } do |f| %>

and add in this is _form this:

<p>
<%= f.file_field :photo %>
  </p>

in Index.html.erb:

in Show.html.erb :

Getting info from params into model rails paperclip app

4 Answers4