Is Array constants in the model can be changed during runtime?

Rails
#1

Hello everyone!

I have strange problem. Here is the code:

model:

class ItServiceJob < ActiveRecord::Base
TYPES = [[“Important”, 0], [“Not important”, 1], [“SERGEY”, 2]]

belongs_to :userend

view (haml):

%div{:role => “main”, :class => “ui-content”}
- job_types = ItServiceJob::TYPES
- job_types.pop if (!can?(:manage, :it_service) || !can?(:born,
:sergey))
= job_types
= form_for ItServiceJob.new, url: “#” do |f|

  %p
    = f.label :type
    = f.select :type, job_types

Now, when I refresh the page every time, the array pops one by one item
and
finally get empty! But, why? Why the constant changes, not variable?
What
I’m doing wrong?

#2

Hi,

Constants in Ruby are “contantish”. And in your case you’re passing the
array reference to job types, so any changes that you do in job_types it
goes to ItServiceJob::TYPES.

With that being said what you need to do is duplicate the
ItServiceJob::TYPES. Change the job_type assignment with:

job_types = ItServiceJob::TYPES.dup

Regards,

Marco Antonio A.+45 31 65 28 84
Twitter: @marcoafilho http://www.twitter.com/marcoafilho | LinkedIn:
marco-antonio-almeida-filhohttp://www.linkedin.com/pub/marco-antonio-almeida-filho/53/399/3a2

#3

On Monday, February 3, 2014 9:36:25 AM UTC, Роман Ярыгин wrote:

Now, when I refresh the page every time, the array pops one by one item
and finally get empty! But, why? Why the constant changes, not variable?
What I’m doing wrong?

What is constant is that ItServiceJob::TYPES always gives you the same
object (in terms of it object_id), but there is nothing to stop you
modifying the object.

Furthermore, job_types = ITServiceJob::TYPES isn’t copying
ItServiceJob::TYPES, it is just creating a local variable that
references
the exact same ruby object. You can copy the array with .dup (this is a
shallow copy). If you want to prevent modifications to an object you
need
to freeze it (by calling .freeze on it). After this any attempts to
modify
the object will raise an exception

Fred

#4

On 3 February 2014 10:50, Arun kant sharma [email protected] wrote:

Sorry for off topic reply, but how do you quote code using gmail? or I
should use web interface for posting in group.

Click on the three dots on the bottom left of the input text window to
expand the text.

Colin

#5

Sorry for off topic reply, but how do you quote code using gmail? or I
should use web interface for posting in group.

On Mon, Feb 3, 2014 at 3:23 PM, Frederick C.
<[email protected]

#6

Oops, I meant code snippets. How to insert them in gmail?

#7

Thank you for the answers! Will try at work tomorrow!

P.S. I just copy-paste formatted text from another forum =)

#8

On 3 February 2014 11:15, Arun kant sharma [email protected] wrote:

Oops, I meant code snippets. How to insert them in gmail?

Copy/Paste. Best to keep it plain text. IMO at least.

Colin