csv_mapper_data_type_example.rb

# Given a CSV record format like:
# john,doe,blonde,26

CsvMapper.import('blah') do
  map_to Person

  first_name # maps to string by default
  last_name  # maps to string by default

  _SKIP_   # skip the 'hair color' column

  # but age should be an integer...
  age.map {|row, index| row[index].to_i}
end

future.rb

# Given
class Business
  attr_accessor :name, :net_worth
  attr_accessor :address
  attr_accessor :employees
end

class Address
  attr_accessor :line_1, :line_2, :city, :state, :zip
end

class Employee
  attr_accessor :first_name, :last_name
end

# Import with CSV Mapper
CsvMapper.map_to(Business).import('path') do |config|
  config.start_at_row 1      # Skip the first row (probably a header row)
  config.stop_at_row 10      # Stop parsing on the 10th row

  name                       # Parse to String by default
  net_worth :type => Float   # Parse column value Float

  # Map an aggregate model that is an instance of Address
  address.map_to Address do 
    line_1
    line_2
    city
    state.map {|value| value.to_s.upcase}   # Parse the raw value using the given block
    zip
  end

  # Map a collection of employees that are instances of Employee
  employees.map_to Employee, :count => 2 do
    first_name
    last_name
  end
end

# Results - An array of two instances of a Business; each with a fully populated Address instance as the value of the address attribute