Contents

module Scrapify
  module Base
    def self.included(klass)
      klass.extend ClassMethods
      klass.cattr_accessor :url, :doc, :attribute_names
    end

    module ClassMethods
      def html(url)
        self.url = url
        define_finders
      end

      def attribute(name, options={})
        add_attribute(name)
        parser = options[:xpath] ? :xpath : :css
        selector = options[parser]
        meta_define "#{name}_values" do
          self.doc ||= parse_html
          self.doc.send(parser, selector).map &:content
        end
      end

      def key(attribute)
        define_find_by_id attribute
        define_count attribute
      end

      private

      def add_attribute(name)
        self.attribute_names ||= [] 
        self.attribute_names << name
      end

      def parse_html
        Nokogiri::HTML(open(url))
      end

      def define_finders
        meta_define :all do
          count.times.map do |index|
            find_by_index index
          end
        end

        meta_define :first do
          find_by_index 0
        end

        meta_define :last do
          find_by_index count - 1
        end

        meta_define :find_by_index do |index|
          return if index.nil? or index < 0
          attributes = Hash[attribute_names.map {|attribute| [attribute, send("#{attribute}_values")[index]]}]
          OpenStruct.new(attributes)
        end
      end

      def define_count(key_attribute)
        meta_define :count do
          send("#{key_attribute}_values").size
        end
      end

      def define_find_by_id(key_attribute)
        meta_define :find do |key_value|
          index = send("#{key_attribute}_values").index(key_value)
          find_by_index index
        end
      end
    end
  end
end

Version data entries

1 entries across 1 versions & 1 rubygems

Version	Path
scrapify-0.0.1	lib/scrapify/base.rb