How to upload photos in rails 4? - ruby-on-rails

Question

https://gist.github.com/Gtar69/27139cee82c75992ed82
Mac OS 10.9.3
Rails 4.1.0
Now I want to add photo upload to my website ! In that way, in terminal=>
$ rails g model Photo image_name:string product:references
$ rake db:migrate
$ rails g migration add_image_to_photos image:string
$ rake db:migrate
$ rails g controller Photos
Scheme as below:
ActiveRecord::Schema.define(version: 20140612034245) do
create_table "photos", force: true do |t|
t.string "image_name"
t.integer "product_id"
t.datetime "created_at"
t.datetime "updated_at"
t.string "image"
end
config/routes.rb
Rails.application.routes.draw do
devise_for :users
namespace :admin do
resources :products do
resources :photos
end
end
end
For new created controller, PhotosController shown below"
class PhotosController < ApplicationController
def create
#product = Product.find(params[:product_id])
#photo = #product.photos.create(photo_params)
redirect_to admin_product_path(#product)
end
private
def photo_params
params.require(:photo).permit(:image_name, :iamge)
end
end
Finally, adding "upload photos feature" in new.html.erb
<div class="panel panel-default">
<div class="panel-body">
<%= simple_form_for [:admin, #product] do|f| %>
<div class="group">
<%= f.input :title, label:'標題' %>
</div>
<div class="group">
<%= f.input :description, label:'敘述'%>
</div>
<div class = "group">
<%= f.input :quantity, label:'數量' %>
</div>
<h2>Add Photos</h2>
<%= form_for([#product, #product.photos.build]) do |f| %>
<% end %>
<%= f.submit "Submit", :disable_with => 'Submiting...' %>
</div>
</div>
However, I encounter the problem I can't understand =>
Rendered admin/products/new.html.erb within layouts/application (18.8ms)
Completed 500 Internal Server Error in 57ms
Showing /Users/Gtar/projects/artstore/app/views/admin/products/new.html.erb where line #26 raised:
undefined method `product_photos_path' for #<#<Class:0x000001013b2ef8>:0x00000101118670>
ActionView::Template::Error (undefined method `product_photos_path' for #<#<Class:0x000001013b2ef8>:0x00000101118670>):
23: </div> form_for([#article, #article.comments.build]) do |f| %>
24: -->
25: <h2>Add Photos</h2>
26: <%= form_for([#product, #product.photos.build]) do |f| %>
27: <% end %>
28: <%= f.submit "Submit", :disable_with => 'Submiting...' %>
29: </div>
app/views/admin/products/new.html.erb:26:in `block in _app_views_admin_products_new_html_erb__2984465001892677316_2165881840'
app/views/admin/products/new.html.erb:8:in `_app_views_admin_products_new_html_erb__2984465001892677316_2165881840'
Would you mind helping me for solve the issure?

Answer 1

Routes
For reference for future readers, here's your error:
undefined method `product_photos_path'
--
The problem here, as stated in the comments, is you're referencing a nested route, which doesn't exist. You'll need to do something like this in your routes:
#config/routes.rb
#no namespace
resources :products do
resources :photos #-> domain.com/products/1/photos
end
This will give you the route you need. You're currently using a namespace, which means you'll have to reference something like admin_product_photos_path
Paperclip
Something else you should consider is paperclip
This is a gem which helps you upload & save files to your database. It works much the same as you have now, except it uses its own datatable structure, with a call in your model to define the object:
#app/models/photo.rb
Class Photo < ActiveRecord::Base
has_attached_file :image
validates_attachment_content_type :image, :content_type => /\Aimage\/.*\Z/
end
This will allow you to call the image object like this:
#product = Product.find params[:id]
#product.photos.first.image #-> image object from Paperclip
If you'd like more information, I would recommend you use this Railscast: