From: Robert Klemme <shortcutter@...>
Date: 2007-06-28T21:00:03+09:00
Subject: Re: Dynamic sort_by criteria, making it DRY...

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