pancakes¶ ↑

Parse fixed width files into Ruby object model.

DESCRIPTION¶ ↑

FEATURES/PROBLEMS:¶ ↑

• Friendly DSL

• Map fixed width fields to Ruby attributes

• Key based relationships - has_one, has_many

SYNOPSIS:¶ ↑

Fixed width file order.txt:

ORD         123
ORD_HEADER  a special order
ORD_L       1    car engine400.99
ORD_L       2    toothpick   1.99

Ruby code to parse above file:

class Order < Pancakes::PositionalPancake
  field :order_id, :position => 12..16

  has_one  :order_header, :key => "ORD_HEADER"
  has_many :order_lines,  :key => "ORD_L"
end

class OrderHeader < Pancakes::PositionalPancake
  field :description, :position => 12..21
end

class OrderLine < Pancakes::PositionalPancake
  field :line_num,    :start => 12..16, :as => :integer
  field :description, :start => 17..26
  field :price,       :start => 27..32, :as => :float
end

File.open("order.txt") do |f|
  order = Order.load(f)

  puts order.order_id                 # => '123'
  puts order.order_header.description # => 'a special order'

  order.order_lines.each do |order_line|
    puts "line num: #{order_line.line_num}, price: #{order_line.price}"
  end
end

Copyright¶ ↑

Copyright © 2010 Steve Molitor. See LICENSE for details.