Rails - Jul 2006 - ActiveRecord design question

Hi everyone, I have a small design question.

My app has the classical ''User'' table.  The problem is that I
will
probably have a lot of user set options.  I did not want to add 20-30 
fields to the user table so I created a user_options table:

==============================class User < ActiveRecord::Base
  has_many :user_options
end
==============================class UserOption < ActiveRecord::Base
  belongs_to :user
end
==============================
Unfortunately this does not give me what I want.  My problem is the 
following:  I would like to be able to reference the user_options like 
this: 

user = User.find(:first)
user.user_options[:key] => this would return :value

But unfortunately the way I did it does not work like this.  I have to 
go through the user.user_options array and find the proper key and I 
cannot figure out how to accomplish this...

Any idea how I could do this?

Thank you in advance,

Jd

P.S.  Would there also be a simple rails way to verify that there is 
indeed a value set for the given :key, and if not give it a default 
value?  I''ve been trying to make this work,but I''m still very
new to rails.

> user = User.find(:first)
> user.user_options[:key] => this would return :value
Try:

class User < AR::Base
  has_many :user_options do
    def [](*args)
      ... search code goes here...
    end
  end
end

-- 
Posted via http://www.ruby-forum.com/.

Dr Nic wrote:
>> user = User.find(:first)
>> user.user_options[:key] => this would return :value
>>     
>
> Try:
>
> class User < AR::Base
>   has_many :user_options do
>     def [](*args)
>       ... search code goes here...
>     end
>   end
> end
>
>   
This is very neat I had no idea you would do this....However seem I''m 
too much of a newbie to figure it out completely on my own.

Now using your snippet of code, my search code is, in effect, in the 
user_options class.  What am I trying to do is reach the 
user.user_options array and search through it with something like 
user_options.find {|opt| opt.key==key}.  Unfortunately I can''t manage
to
reach the user_options array, since I am in the user_options class.  And 
since the user_options class doesn''t inherit from User, I
can''t use ''super''.

I guess I could query the database, but I taught it would be simpler and 
more DRY to reuse the user.user_options array, since I wouldn''t have to
deal with the database at all like this.  (And I could also use another 
method like def[]=(*args) to put values back in the user_options without 
dealing directly with the db).

Any help would be greatly appreciated.


Here a non-working example of what i''m trying to do (I just improvised 
the def []= so it could veyr well not work the way it''s written atm):

class User < AR::Base
  has_many :user_options do
    def [](key)
      return super.user_options.find {|opt| opt.key==key}
    end

    def []=(key, value)
	super.user_options.each do |opt| 
	    if opt.key==key 
		opt.value=value
	    end
	end
    end
  end

end