Seven Languages in Seven Weeks: Ruby, Day 3

csv_new.rb

module ActsAsCsv
  def self.included(base)
    base.extend ClassMethods
  end
  
  module ClassMethods
    def acts_as_csv
      include InstanceMethods
      include Enumerable
    end
  end
  
  module InstanceMethods
    attr_accessor :headers, :csv_contents
    
    def initialize
      read
    end
    
    def read
      @csv_contents = []
      filename = self.class.to_s.downcase + '.csv'
      file = File.new(filename)
      
      @headers = parse_row file.gets
            
      file.each do |row|
        @csv_contents << CsvRow.new(@headers, parse_row(row))
      end
    end
    
    def parse_row(row)
      row.chomp.split(', ')
    end
    
    def each
      @csv_contents.each { |row| yield row }
    end
        
    class CsvRow
      def initialize(headers, row)
        @headers = headers
        @row = row
      end
      
      def respond_to?(sym)
        @headers.index(name.to_s) || super(sym)
      end
      
      def method_missing name, *args, &block
        index = @headers.index(name.to_s)
        if index
          @row[index]
        else
          super
        end        
      end      
    end
  end
end

class RubyCsv
  include ActsAsCsv
  acts_as_csv
end

csv = RubyCsv.new
puts csv.headers.inspect
puts csv.csv_contents.inspect
csv.each { |row| puts "#{row.name}, #{row.age}" }

csv_new_output.txt

$ ruby csv_new.rb
["name", "location", "age"]
[#<ActsAsCsv::InstanceMethods::CsvRow:0x25814 @row=["Jim", "Menlo Park", "27"], @headers=["name", "location", "age"]>, #<ActsAsCsv::InstanceMethods::CsvRow:0x25738 @row=["Bob", "Palo Alto", "37"], @headers=["name", "location", "age"]>, #<ActsAsCsv::InstanceMethods::CsvRow:0x2565c @row=["Steve", "NYC", "28"], @headers=["name", "location", "age"]>]
Jim, 27
Bob, 37
Steve, 28

csv_original.rb

module ActsAsCsv
  def self.included(base)
    base.extend ClassMethods
  end
  
  module ClassMethods
    def acts_as_csv
      include InstanceMethods
    end
  end
  
  module InstanceMethods
    attr_accessor :headers, :csv_contents
    
    def initialize
      read
    end
    
    def read
      @csv_contents = []
      filename = self.class.to_s.downcase + '.csv'
      file = File.new(filename)
      
      @headers = file.gets.chomp.split(', ')
            
      file.each do |row|
        @csv_contents << row.chomp.split(', ')
      end
    end  
  end
end

class RubyCsv
  include ActsAsCsv
  acts_as_csv
end

csv = RubyCsv.new
puts csv.headers.inspect
puts csv.csv_contents.inspect

csv_original_output.txt

$ ruby csv_original.rb 
["name", "location", "age"]
[["Jim", "Menlo Park", "27"], ["Bob", "Palo Alto", "37"], ["Steve", "NYC", "28"]]

LinkedInProfile.rb

class LinkedInProfile
  SIMPLE_PROFILE_FIELDS = %w[id summary headline honors interests specialties industry first_name last_name public_profile_url picture_url associations]

  SIMPLE_PROFILE_FIELDS.each do |field|
    define_method(field.to_sym) do
      @json[field]
    end
  end

  def initialize(json)
    @json = json
  end
end

rubycsv.csv

See Seven Languages in Seven Weeks: Ruby, Day 3 for more information.