CONST initialization

ruby-talk
1

How come this works when I access Orders::PAYMENT_TYPES

CODE

class Order < ActiveRecord::Base
  PAYMENT_TYPES = [
    [ "Check", "check" ],
    [ "Credit card", "cc" ],
    [ "Purchase order", "po" ]
  ]

  has_many :line_items

  validates_presence_of :name, :address, :email, :pay_type
  validates_inclusion_of :pay_type, :in => PAYMENT_TYPES.map {|disp,
value> value}

end
<<<<<<<<<< CODE

But this doesn't:

CODE

class Order < ActiveRecord::Base
  has_many :line_items

  validates_presence_of :name, :address, :email, :pay_type
  validates_inclusion_of :pay_type, :in => PAYMENT_TYPES.map {|disp,
value> value}

  PAYMENT_TYPES = [
    [ "Check", "check" ],
    [ "Credit card", "cc" ],
    [ "Purchase order", "po" ]
  ]

end
<<<<<<<<<< CODE

Error thrown:
/usr/lib/ruby/gems/1.8/gems/activesupport-1.4.2/lib/active_support/dependencies.rb:477:in
`const_missing'

I have moved the PAYMENT_TYPES map around and it even is okay if it's
after the has_many :item_lines accessor, but not if it's after the
'validation' accessors.

Thanks.

···

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Posted via http://www.ruby-forum.com/.

2

I think you've answered your own question, but you might not understand why. The ruby interpreter is "executing" each line within the class definition as it is encountered. If there's no PAYMENT_TYPES when the validates_inclusion_of line is reached, it really doesn't matter that it *does* appear later in the class definition.

-Rob

Rob Biedenharn http://agileconsultingllc.com
Rob@AgileConsultingLLC.com

···

On Jul 5, 2007, at 3:12 PM, Jean Nibee wrote:

How come this works when I access Orders::PAYMENT_TYPES

Error thrown:
/usr/lib/ruby/gems/1.8/gems/activesupport-1.4.2/lib/active_support/dependencies.rb:477:in
`const_missing'

I have moved the PAYMENT_TYPES map around and it even is okay if it's
after the has_many :item_lines accessor, but not if it's after the
'validation' accessors.

Thanks.

3

Rob Biedenharn wrote:

···

On Jul 5, 2007, at 3:12 PM, Jean Nibee wrote:

Thanks.

I think you've answered your own question, but you might not
understand why. The ruby interpreter is "executing" each line within
the class definition as it is encountered. If there's no
PAYMENT_TYPES when the validates_inclusion_of line is reached, it
really doesn't matter that it *does* appear later in the class
definition.

-Rob

Rob Biedenharn http://agileconsultingllc.com
Rob@AgileConsultingLLC.com

Doh..

Sorry I"m still in 'vm' world w/ my Java code thinking that a Ruby class
is ONLY a definition, I forget to realize it's being interpreted as it's
being read.

Thanks for the wake up.

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