Forum: Ruby on Rails Aggregation: problem with uninitialized composed_of object

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Adriano (Guest)
on 2009-01-16 20:17
(Received via mailing list)
Hi,

I'm getting this error:

>> p = Plan.new
>> p.amount
TypeError: wrong argument type String (expected Fixnum)

Apparently this happens because the aggregation isn't initialized.
Here's the code:

class Plan < ActiveRecord::Base
    composed_of :amount,
              :class_name => "Money",
              :converter  => Proc.new { |s| Money.new(s) },
              :mapping    => [:price, :value]
end

class Money
  attr_reader :value

  def initialize(string)
    @value = BigDecimal(string.sub(/,/, '.'))
  end

  def to_s
    Integer(@value * 100).to_s.sub(/(\d{2})$/, ',\1')
  end
end

I would like to hide the aggregation from controllers...

There's the after_initialization callback where I could (try to)
initialize the value object if it is nil...

I wonder what's the proper way to deal with this situation?

Thanks,

--
Adriano
Adriano N. (Guest)
on 2009-01-17 03:18
(Received via mailing list)
For the record...

On Jan 16, 4:17 pm, Adriano <removed_email_address@domain.invalid> wrote:
> TypeError: wrong argument type String (expected Fixnum)

[snip]

>   def initialize(string)
>     @value = BigDecimal(string.sub(/,/, '.'))
>   end

The problem was that value object can be initialized with a string
(from the form) or with a number (from the db). Thus initialize should
be changed, eg:

def initialize(value)
  @value = BigDecimal(value.to_s(/,/, '.'))
end

--
Adriano
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