Why has_many doesn't set target for objects in its collection?
E.g. when
class Author < ActiveRecord; has_many :posts; end
class Post < ActiveRecord; belongs_to :author; end
then
some_author.posts.each {|p| puts p.author.name}
will require additional queries to fetch author for each post.
Could some option to has_many be added to pre-fill the target (in this
case set_author_target for each post)?
Something like:
module ActiveRecord
module Associations # :nodoc:
module ClassMethods
# When called with <tt>:fill_target => name</tt> it will fill
targets in each object in association
# E.g.: when Author <tt>has_many :posts, :fill_target =>
"author"</tt>
# then <tt>some_author.posts.each {|m| m.author.name }</tt> will
not require aditional db queries to fetch author for each post
# (it will use the +some_author+ already from memory)
#
# Two methods are created additionally, for the example above it
will be +posts_with_author+ and +posts_without_author+,
# where just +posts+ is the same as +posts_with_author+
def has_many_with_fill_target(association_id, options = {},
&extension)
fill_target = options.delete(:fill_target)
has_many_without_fill_target(association_id, options,
&extension)
if fill_target
module_eval do
define_method("#{association_id}_with_#{fill_target}") do |
*args|
returning( send("#{association_id}_without_#{fill_target}", *args) ) {|
p| p.each {|m| m.send("set_#{fill_target}_target", self) } }
end
alias_method_chain association_id, fill_target
end
end
end
alias_method_chain :has_many, :fill_target
end
end
end
--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups "Ruby
on Rails: Core" group.
To post to this group, send email to [email protected]
To unsubscribe from this group, send email to [EMAIL PROTECTED]
For more options, visit this group at
http://groups.google.com/group/rubyonrails-core?hl=en
-~----------~----~----~----~------~----~------~--~---
