Rails - May 2005 - updating habtm from a form

I''m trying to (cleanly) update a habtm Model after a form submission.

Along with everything else in the form (that relates to the Account 
Model) I have a series of checkboxes:
<%= check_box_tag "account[roles][]", role.id, 
@account.roles.include?(role) %>

That all works right, so upon submission, my AccountController does this:
def update
  @account = Account.find(@params[:id])
  @account.roles.clear
  @account.roles << Role.find(@params[:roles]) if @params[:roles]
  if @account.update_attributes(@params[:account])
    ...
  end
end

That also works fine... the problem is, I don''t want to have to do all 
of that manually (I have a ton of habtm''s).  Isn''t there an
easy way to
make that habtm association update the related tables automagically?  I 
tried overwriting the update_attributes method in my Accounts Model:

def update_attributes(params)
  roles.clear
  roles << Role.find(params[:roles]) if params[:roles]
  super
end

Which kind of works, but there''s an exception raised when 
ActiveRecord::Base tries to store params[:roles] (which typically looks 
like ["1", "3", "4"]) as Roles in the related
table.

I''d love to hear some tips, thanks,
Mike

Mike Evans <mike-FpmKrjSK9lFgyGvZe3TC8g@public.gmane.org> writes:
> def update_attributes(params)
>  roles.clear
>  roles << Role.find(params[:roles]) if params[:roles]
>  super
> end
>
> Which kind of works, but there''s an exception raised when 
> ActiveRecord::Base tries to store params[:roles] (which typically looks 
> like ["1", "3", "4"]) as Roles in the related
table.
Search the archives for "habtm and checkboxes".  We''ve just
finished
up a nice thread this week that covers this quite well.
-- 
doug-jGAhs73c5XxeoWH0uzbU5w@public.gmane.org

On 5/20/05, Mike Evans <mike-FpmKrjSK9lFgyGvZe3TC8g@public.gmane.org>
wrote:
> I''m trying to (cleanly) update a habtm Model after a form
submission.
> 
> Along with everything else in the form (that relates to the Account
> Model) I have a series of checkboxes:
> <%= check_box_tag "account[roles][]", role.id,
> @account.roles.include?(role) %>
> 
> That all works right, so upon submission, my AccountController does this:
> def update
>   @account = Account.find(@params[:id])
>   @account.roles.clear
>   @account.roles << Role.find(@params[:roles]) if @params[:roles]
>   if @account.update_attributes(@params[:account])

I notice Mike is using symbols as hash keys there; the examples I''ve
seen use strings ''id'', ''roles'', and so on,
so that''s what I''ve been
using.  Is one more "correct" than the other, or more standard, or
does it matter.  Can there be a case where one works and the other
doesn''t?

On Saturday 21 May 2005 16:19, Michael Campbell wrote:
> I notice Mike is using symbols as hash keys there; the examples
I''ve
> seen use strings ''id'', ''roles'', and so
on, so that''s what I''ve been
> using.  Is one more "correct" than the other, or more standard,
or
> does it matter.  Can there be a case where one works and the other
> doesn''t?
I''m wondering the same all the time. Rails internally extends Hash 
(through HashWithIndifferentAccess) to be agnostic regarding the 
string/symbol distinction. That doesn''t help me much, though, when 
trying to decide how to write my own code.

Michael

-- 
Michael Schuerig                 Not only does lightning not strike
mailto:michael-q5aiKMLteq4b1SvskN2V4Q@public.gmane.org       twice, it usually
doesn''t strike once.
http://www.schuerig.de/michael/  --Salman Rushdie, Fury

On 6/3/05, Michael Schuerig
<michael-q5aiKMLteq4b1SvskN2V4Q@public.gmane.org>
wrote:
> On Saturday 21 May 2005 16:19, Michael Campbell wrote:
> 
> > I notice Mike is using symbols as hash keys there; the examples
I''ve
> > seen use strings ''id'', ''roles'',
and so on, so that''s what I''ve been
> > using.  Is one more "correct" than the other, or more
standard, or
> > does it matter.  Can there be a case where one works and the other
> > doesn''t?
> 
> I''m wondering the same all the time. Rails internally extends Hash
> (through HashWithIndifferentAccess) to be agnostic regarding the
> string/symbol distinction. That doesn''t help me much, though, when
> trying to decide how to write my own code.
>From what I gather on IRC, it doesn''t matter.  But, to be
consistent
with "current wisdom", I''m using symbols now.