feedfu/app/models/feed.rb

require "pp"

class Feed < ActiveRecord::Base
  has_many :items, :dependent => :destroy
  has_many :errors, :dependent => :destroy

	validates_uniqueness_of :url

	default_scope where(:has_errors => false)
	scope :with_error, unscoped.where(:has_errors => true)

	def fetch!
    Feedzirra::Feed.fetch_and_parse(url,
			:on_success => lambda do |url, feed|
        begin
          feed.entries.each do |entry|
            unless Item.exists?(:url => entry.url)
              entry.sanitize!
              items << Item.create_from_feed_entry!(entry)
            end
          end
          by_url(url).update_attribute(:has_errors, false)
        rescue Exception => e
          Error.create!(:feed_id => self.id, :action => :fetch_and_parse,
                        :message => e)
        end
			end,
      :on_failure => lambda do |url, response_code, response_header, response_body|
        by_url(url).update_attribute(:has_errors, true)
        Error.create!(:feed_id => self.id, :action => :fetch_and_parse,
                      :message => "
        url: #{url}
        response-code: #{response_code}
        response-header: #{response_header}
        response-body: #{response_body}
                      ")
      end
		)
	end

	def self.import(url, *params)
    Feedzirra::Feed.fetch_and_parse(url,
      :on_success => lambda do |url, feed|
        Feed.create!(:url => feed.feed_url, :title => feed.title).fetch!
      end,
      :on_failure => lambda do |url, response_code, response_header, response_body|
        if params.first.include?(:force)
          feed = Feed.create!(:url => url, :has_errors => true)

        Error.create!(:feed_id => feed.id, :action => :import,
                      :message => "
        url: #{url}
        response-code: #{response_code}
        response-header: #{response_header}
        response-body: #{response_body}
                      ")
        end
      end
    )
	end

  def self.update_all!
    Feed.all.each do |feed|
      feed.fetch!
    end
  end

	private
	def by_url(feed_url)
		Feed.where(:url => feed_url).first
	end
end