Contents

module Lifestream
  class Channel
    
    attr_accessor :name, :branches, :raw_text, :feed
    
    def initialize name, url
      @name, @branches, @request = name, [], Lifestream::Request.new(url)
    end
    
    def branches
      create_branches if @branches.empty?
      @branches
    end
    
    protected
    
    def download
      response_with_cache do
        response = @request.get
        raise unless response.kind_of?(Net::HTTPSuccess)
        @raw_data = response.body
      end
    rescue => e
      raise Lifestream::Channel::DownloadError.new("The URL #{@request.url} failed to download. #{e}") if Lifestream.options[:whiny]
    end
    
    def response_with_cache
      yield and return unless Lifestream.options[:cache]
      cache_path = File.join(Lifestream.options[:cache], "#{name}.xml")
      if !File.exist?(cache_path) || File.mtime(cache_path) + Lifestream.options[:cache_expiration] < Time.now
        yield
        cache = File.new(cache_path, 'wb')
        cache.flock(File::LOCK_EX)
        cache.write(@raw_data)
        cache.flock(File::LOCK_UN)
      else
        @raw_data = File.read(cache_path)
      end
    end
    
    def create_branches
      download
      parse
      feed_to_a.each do |item|
        @branches << to_branch(item)
      end
    end
    
    def parse
      raise_method_error :parse
    end
    
    def feed_to_a
      raise_method_error :feed_to_a
    end
    
    def to_branch
      raise_method_error :to_branch
    end
    
    private
    
    def raise_method_error method
      raise Lifestream::Channel::MethodError, "Method `#{method}' must be overriden in the child class"
    end
    
    class MethodError < StandardError; end
    class DownloadError < StandardError; end
    
  end
end

Version data entries

1 entries across 1 versions & 1 rubygems

Version	Path
lifestream-0.1.5	lib/lifestream/channel.rb