Rails - Jun 2008 - Sorting an array of Hash on two fields one of it is optional

Hi,

I need to sort an array of Hash - an array whose elements are hash
variable - a hash of name and email. Name is an optional field , ie it
can be nil but email is always not NULL.

How do I sort the array of these hash variables? SOrt on names. But if
name is nil, then sort on emailID.

 @contacts =  @my_contacts.sort! do |a,b|

         if a["name"] != nil  && b["name"] != nil
       n = a["name"] <=> b["name"]
   end
   if a["name"].nil?
      n == 0 ? a["email"] <=> b["name"] :n
   else
      n == 0 ? a["name"] <=> b["email"]:n
   end
   n == 0 ? a["email"]<=> b["email"]:n

  end

1. Name = A email=Z@a.com
2. Name = B email=b@a.com
3. Name = nil email=a@c.com

sort on this shud result in
1. Name = A email=Z@a.com
3. Name = nil email=a@c.com - Name A wins over name nil
2. Name = B email=b@a.com  - email a@c.com wins over name B

But i am getting comparision of hash and hash failed - Error.

Pleas help.

Regards,
Sandeep G
-- 
Posted via http://www.ruby-forum.com/.

--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"Ruby on Rails: Talk" group.
To post to this group, send email to
rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
To unsubscribe from this group, send email to
rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
For more options, visit this group at
http://groups.google.com/group/rubyonrails-talk?hl=en
-~----------~----~----~----~------~----~------~--~---

On Sun, Jun 1, 2008 at 3:11 PM, Sandeep Gudibanda <
rails-mailing-list-ARtvInVfO7ksV2N9l4h3zg@public.gmane.org> wrote:
>
> Hi,
>
> I need to sort an array of Hash - an array whose elements are hash
> variable - a hash of name and email. Name is an optional field , ie it
> can be nil but email is always not NULL.
>
> How do I sort the array of these hash variables? SOrt on names. But if
> name is nil, then sort on emailID.
>
>  @contacts =  @my_contacts.sort! do |a,b|
>
>         if a["name"] != nil  && b["name"] !=
nil
>       n = a["name"] <=> b["name"]
>   end
>   if a["name"].nil?
>      n == 0 ? a["email"] <=> b["name"] :n
>   else
>      n == 0 ? a["name"] <=> b["email"]:n
>   end
>   n == 0 ? a["email"]<=> b["email"]:n
>
>  end
>
> 1. Name = A email=Z@a.com
> 2. Name = B email=b@a.com
> 3. Name = nil email=a@c.com
>
> sort on this shud result in
> 1. Name = A email=Z@a.com
> 3. Name = nil email=a@c.com - Name A wins over name nil
> 2. Name = B email=b@a.com  - email a@c.com wins over name B
>
> But i am getting comparision of hash and hash failed - Error.


I would just do:

  @contacts = @my_contacts.sort_by {|c| "#{c[:name]}#{c[:email]}" }

This sorts by a new string that is the combination of the name and email. If
the name is nil, nothing will be inserted and it will just have the email

Brandon

--------------------------------------------------------------------------------
Sessions by Collective Idea: Ruby on Rails training in a vacation setting
http://sessions.collectiveidea.com

--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"Ruby on Rails: Talk" group.
To post to this group, send email to
rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
To unsubscribe from this group, send email to
rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
For more options, visit this group at
http://groups.google.com/group/rubyonrails-talk?hl=en
-~----------~----~----~----~------~----~------~--~---

Thats a cool solution! Thanks Brandon!
-- 
Posted via http://www.ruby-forum.com/.

--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"Ruby on Rails: Talk" group.
To post to this group, send email to
rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
To unsubscribe from this group, send email to
rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
For more options, visit this group at
http://groups.google.com/group/rubyonrails-talk?hl=en
-~----------~----~----~----~------~----~------~--~---