Rails - May 2006 - Missing documentation for find_in_collection? Trying to drill down in a 4 level has_many association fails

I''ve been reading up in ActiveRecord::Associations and playing around  
with my app via the console and found some interesting methods via  
the code completion of IRB, but I have no idea how to use them and  
can only find one hint in the API
http://api.rubyonrails.com/classes/ActiveRecord/Associations/ 
ClassMethods.html

It mentions here in the has many associations that if you use the  
finder_sql that you would loose the find_in_collection. What are  
these and the find_all_in_collection methods I am finding. For  
example the simple models i am using is a 4-tier has_many structure  
like this:

class User < ActiveRecord::Base
   has_many      :foos,
end

class Foo < ActiveRecord::Base
   belongs_to    :user
   has_many      :bars,
end

class Bar < ActiveRecord::Base
   belongs_to    :foo
   has_many      :mistakes,
end

class Mistake < ActiveRecord::Base
   belongs_to    :bar
end

So while in IRB via the console of my app, I can do this and see all  
the following options via command completion on the next step.

 >> @user = User.find(1)
=> #<User:0x26eb9cc @attributes={...
 >> @user.find
@user.find                             
@user.find_collection_for_pagination   
@user.find_mapped_obj_class           @user.find_tag
@user.find_all                         
@user.find_first                       
@user.find_mapped_soap_class          @user.find_target
@user.find_all_in_foos              
@user.find_first_recursive             
@user.find_name                       @user.find_user_object
@user.find_all_tag                     
@user.find_in_foos                  
@user.find_plugins                     
@user.finding_with_ambigious_select?
 >> @user.find_in_foos(1)
=> #<Foo:0x26a0008 @attributes={

It''s really crazy, I can use that method @user.find_in_foos(1) and  
get an object that belongs to the user and once that is done, it  
opens up more find commands (specifically find_all_in_bars and  
find_in_bars) to the next layer in my tier. So now I want to try and  
find an associated object to the user by using the new methods. But  
it fails if the association is more than 1 deep. So for example...

 >> @user.find_in_bars(1)
NoMethodError: LOG:  duration: 468.984 ms  statement: SELECT * FROM  
columns WHERE (foos.user_id = 1)  ORDER BY position
undefined method `find_in_bars'' for #<User:0x26eb9cc>
         from /opt/local/lib/ruby/gems/1.8/gems/activerecord-1.14.2/ 
lib/active_record/base.rb:1792:in `method_missing''
         from (irb):3

These methods look like they would be fun to use. Ultimately I just  
want to find an object thru an association starting at the top. Any  
feedback advise?


  - Ken



-------------- next part --------------
An HTML attachment was scrubbed...
URL:
http://wrath.rubyonrails.org/pipermail/rails/attachments/20060505/9e8fee60/attachment.html