StackOverflow2013

Note that there are some explanatory texts on larger screens.

plurals

POusing "self" in association declaration (:has_many, :has_one)
primarykey
Id
4564444
data
AcceptedAnswerId
4565765
AnswerCount
3
ClosedDate
CommentCount
0
CommunityOwnedDate
CreationDate
2010-12-30T16:44:04.623
FavoriteCount
0
LastActivityDate
2010-12-30T19:51:16.373
LastEditDate
LastEditorUserId
0
OwnerUserId
365738
ParentId
0
PostTypeId
1
Score
2
ViewCount
818
LastEditorDisplayName
text
Body
I need to reference a model's self in a :has_many declaration. I have a class we will call Foo. Foo :has_many Bar. Foo has a boolean attribute called randomize that determines the order of the the Bars in the :has_many relationship. If randomize is true, then they are ordered by "RAND()" or "RANDOM()" depending on the DB. If not, they are ordered by id. I HAVE to make this declaration on the association because I am using eager loading. I am well-aware that I can define a method in Foo that returns what I want, but I need to have everything loaded at once or else 400-500 queries are run individually = bad. <pre><code>class CreateFoo < ActiveRecord::Migration def self.up create_table :foos do |t| t.string :name t.boolean :randomize, :default => false end end end </code></pre>   <pre><code>class CreateBar < ActiveRecord::Migration def self.up create_table :bars do |t| t.string :name t.references :foo end end end </code></pre>   <pre><code>class Bar < ActiveRecord::Base belongs_to :foo end </code></pre>   <pre><code>class Foo < ActiveRecord::Base # this is the line that doesn't work has_many :bars, :order => self.randomize ? 'RAND()' : 'id' end </code></pre> How do I access properties of self in the has_many declaration? Things I've tried and failed: <ol> <li>creating a method of Foo that returns the correct string</li> <li>creating a lambda function</li> <li>crying</li> </ol> Is this possible? The problem seems to be that the "self" in :has_many ISN'T of type Foo: <pre><code>undefined method `randomize' for #<Class:0x1076fbf78> </code></pre> is one of the errors I get. Note that its a general Class, not a Foo Object... Why??
Tags
<ruby-on-rails><activerecord><ruby-on-rails-3>
Title
using "self" in association declaration (:has_many, :has_one)
singulars
PostAcceptedAnswerId
1. PO
 singulars
 PostTypePostTypeId
 PTAnswer
PostParentId
1. This table or related slice is empty.
PostTypePostTypeId
1. PTQuestion
UserLastEditorUserId
1. This table or related slice is empty.
UserOwnerUserId
1. USsethvargo
plurals
PostLinksPostIdRelatedPostId
1. This table or related slice is empty.
PostLinksRelatedPostIdPostId
1. This table or related slice is empty.
PostsAcceptedAnswerId
1. This table or related slice is empty.
PostsParentIdCreationDate
1. PO
 singulars
 PostTypePostTypeId
 PTAnswer
2. PO
 singulars
 PostTypePostTypeId
 PTAnswer
3. PO
 singulars
 PostTypePostTypeId
 PTAnswer
VotesPostIdCreationDate
1. This table or related slice is empty.
CommentsPostId
1. This table or related slice is empty.

Querying!

Guidance

A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.