7 weeks of 7 languages - Ruby Day 3 Metaprogramming

acts_as_csv_module.rb

module ActsAsCsv
    def self.included(base)
        base.extend ClassMethods
    end
    module ClassMethods
        def acts_as_csv
            include InstanceMethods
        end
    end
    module InstanceMethods
        def read
            @rows = []
            filename = self.class.to_s.downcase + '.txt'
            file = File.new(filename)
            @headers = file.gets.chomp.split(', ')
            file.each do |row|
                row = row.chomp.split(', ')
                @rows << CsvRow.new(Hash[*headers.zip(row).flat_map {|i| i}])
            end
        end
        attr_accessor :headers, :rows
        def initialize
            read
        end
        def each(&block)
            @rows.each do |c|
                block.call c
            end
        end
    end
    class CsvRow
        attr_accessor :values
        def initialize(values = {})
            @values = values
        end
        def method_missing name, *args
            @values[name.to_s] if @values.has_key?(name.to_s)
        end
    end
end

class FamilyCsv
    include ActsAsCsv
    acts_as_csv
end

csv = FamilyCsv.new
csv.each do |row|
    puts row.first
    puts row.last
    puts row.relationship
end