From: Josselin <josselin@...>
Date: 2007-06-29T15:15:02+09:00
Subject: Re: Dynamic sort_by criteria, making it DRY... thanks Robert !

On 2007-06-28 23:18:36 +0200, Josselin <josselin@wanadoo.fr> said:

> On 2007-06-28 13:58:47 +0200, Robert Klemme <shortcutter@googlemail.com> said:
> 
>> On 28.06.2007 13:41, Josselin wrote:
>>> I am presently using a sort_by on my array
>>> 
>>> =>    buddies = user_buddies.sort_by {|item| item.last_seen_at}
>>> 
>>> I would like to be able to do the same , based on a variable    
>>> @criteria   set to the item key to be used
>>> 
>>> @criteria = 'last_seen_at'   @criteria = 'display_name' ......
>>> 
>>> =>   buddies = user_buddies.sort_by {|item| item.<@criteria> }
>>> 
>>> what could be the best way to do it ?
>>> 
>>> Depending upon another variable @reverse_order = true or false, I would 
>>> like to perform or not teh reverse! action
>>> 
>>> => buddies = user_buddies.sort_by {|item| item.last_seen_at}.reverse!
>>> 
>>> I believe it should be
>>> 
>>> => buddies =  @reverse_order ? user_buddies.sort_by {|item| 
>>> item.<@criteria> } : user_buddies.sort_by {|item| item.<@criteria> 
>>> }.reverse!
>>> 
>>> thanks for your enlightment !
>> 
>> buddies = user_buddies.sort_by {|it| it.send @criteria}
>> buddies.reverse! if @reverse_order
>> 
>> Kind regards
>> 
>> 	robert
> 
> Thanks Robert cannot be dryest....  I am so ashame of my solution that 
> I don't want to publish my code...

btw , where should I write the 'downcase' method for strings

I tried to write it into the @criteria   (@criteria = 'display_name.downcase' )
which seems to be the right place..

but I got an error
undefined method `display_name.downcase' for #<User:0x34bc34c>

thanks for your complementary solution... ;-))

joss