mitch

[Ruby] On Recreating a list with acts_as_list

2008-07-10T23:47:07-07:00

Michael and zoopzopp:
Thanks for the refactorings, I think the final result is more readable.

Anthony:
I don't like your refactoring because it made me thing about my design too much! :)

I'm really wrestling about your refactoring in my mind. I see the advantages of having an intermediate model for assignments which would create a list. On one hand I don't want that extra model, especially if it just handles the "listing" aspect of widgets. I think a many-to-one association is what I was going for here rather than the many-to-many association that you created.

On the other hand if I ever wanted to work with the assignments more or have the same widget on multiple pages I would definitely do that. In the future a simple list of widgets on a page is probably not going to be enough as a widget may have to be assigned to a column for instance.

>I don't know why you'd want to clear the widgets and instantiate them just to assign them to the page object.

As it stands now I DON'T think that I'm instantiating Widgets here and you ARE instantiating Assignments. Maybe by instantiating you mean looking up the widgets in the database? (Maybe this is a correct use of the term). Still instantiating Assignments (your technique) is probably less expensive than looking up Widgets.

Thanks for the help!

[Ruby] Recreating a list with acts_as_list

2008-07-10T03:27:56-07:00

I tried playing with this a bit but had trouble even making it work. The method gets a list of widgets in a string that looks like "4,3,6,1,12" from jQuery's sortable plugin. "3,1,2" would mean that widget with id==3 is first, id==1 is second and id==2 is last.

The list must be recreated (I think). If an empty string came in that would mean that the page should now have no widgets.

This code looks cryptic to me and may be slow. Thanks for any help!

class Page < ActiveRecord::Base

def assigned_widgets=(string)
  array = string.split(',')
  self.widgets.clear
    
  1.upto(array.size) do |i|
    w = Widget.find(array[i-1])
    w.position = i
    self.widgets << w
  end
end

[Ruby] On ActiveRecord Validations with a lot of conditions

2008-06-06T01:15:13-07:00

One little change. This wasn't working for me and I found a small change from the documentation. Just passing something in the block.

with_options :if => :password_validations_required? do |p|
  p.validates_presence_of     :password
  p.validates_presence_of     :password_confirmation
  p.validates_length_of       :password, :within => 4..40
  p.validates_confirmation_of :password
end

[Ruby] On ActiveRecord Validations with a lot of conditions

2008-06-03T00:42:58-07:00

Thanks so much for the help! I knew that rails must have a way to deal with this but I didn't see it in the documentation.

[Ruby] ActiveRecord Validations with a lot of conditions

2008-05-31T19:49:06-07:00

I've never run into a situation where I wanted to use a lot of conditions on my validations. The way I'm doing it seems a little ridiculous.

in models/user.rb
...  

  validates_presence_of     :email,                      :if => :email_validations_required?
  validates_presence_of     :password,                   :if => :password_validations_required?
  validates_presence_of     :password_confirmation,      :if => :password_validations_required?
  validates_length_of       :password, :within => 4..40, :if => :password_validations_required?
  validates_confirmation_of :password,                   :if => :password_validations_required?
  validates_length_of       :nick,    :maximum => 40,    :if => :nick_validations_required?
  validates_length_of       :email,    :within => 3..100,:if => :email_validations_required?
  validates_format_of       :email, :with => /^([^@\s]+)@((?:[-a-z0-9]+\.)+[a-z]{2,})$/i, 
    :on => :create, :message => "doesn't seem to be valid.",
                                                         :if => :email_validations_required?
  validates_format_of       :nick, :with => /\A[^@]+\Z/i,:if => :nick_validations_required?,
    :message => "can't have a @ in it.  (Sorry, 1337 |-|@><0R5!)"

  validates_uniqueness_of   :login,                      :if => :nick_validations_required?
  validates_uniqueness_of   :email, :case_sensitive => false, :if => :email_validations_required?
...


def password_validations_required?
    (crypted_password.blank? && !using_openid?) || !password.blank?
  end

  def email_validations_required?
    !email.blank? || !using_openid?
  end
  
  def nick_validations_required?
    !nick.blank?
  end

[Ruby] On Better Nest Ifs

2008-05-17T14:22:17-07:00

I know that this is an old thread but I was just confused by all the "!(something.nil?)" refactorings. It think the logic is: If (the key is there) and (the invitation_details_count is less than the total) then it's valid.

def self.valid?(key)
  (h = find_by_key(key)) && (h.invitation_details_count < h.total)
end