Caching Your Photographs

additional_require.rb

require 'open-uri'

cache.rhtml

<% cache do %>
... Your view code here. ...
<% end %>

cache_folders.rb

"#{RAILS_ROOT}/public/images/flickr_cache/small/"
"#{RAILS_ROOT}/public/images/flickr_cache/large/"

cache_method.rb

private
def check_cache
  if ENV['RAILS_ENV'] == 'production'
    flickr = Flickr.new(RAILS_ROOT + "/config/flickr.cache", FLICKR_API_KEY, FLICKR_SHARED_SECRET)
    @photos = flickr.people.getPublicPhotos(flickr.people.findByUsername(FLICKR_USERNAME))
    
    @db_photos = Array.new
    Photo.find(:all).each { |p| @db_photos.push(p.flickr_id) }

    for photo in @photos.reverse
      if !@db_photos.include?(photo.id)
       
        db_photo = Photo.new
        db_photo.flickr_id = photo.id.to_i
        db_photo.title = photo.flickr.photos.getInfo(photo.id).title
        db_photo.description = photo.flickr.photos.getInfo(photo.id).description
        db_photo.url = photo.flickr.photos.getInfo(photo.id).urls.values[0]
          
        db_photo.save
          
        open(File.expand_path("#{RAILS_ROOT}/public/images/flickr_cache/small/" + photo.id + ".jpg"),"w").write(open(photo.url('s')).read)
        open(File.expand_path("#{RAILS_ROOT}/public/images/flickr_cache/large/" + photo.id + ".jpg"),"w").write(open(photo.url).read)
      end
    end
  end
end

controller.rb

def view
  unless read_fragment({})
    check_cache
    @photos = Photo.find(:all)
  end
end

create_model.sh

cd /your/rails/application
./script/generate model Photo

create_photos.rb

class CreatePhotos < ActiveRecord::Migration
  def self.up
    create_table :photos, :id => false do |t|
      t.column "flickr_id", :string, :limit => 25, :null => false
      t.column "title", :string, :limit => 250
      t.column "description", :text
      t.column "url", :string, :limit => 250
    end
    
    add_index :photos, :flickr_id
  end
  
  def self.down
    drop_table :photos
  end
end

photo_page.rhtml

<% for photo in @photos.reverse %>
  <%= image_tag("/images/flickr_cache/small/" + photo.flickr_id + ".jpg", :alt => photo.title) %>
<% end %>