Betternestedset talk - Jan 2007 - ez-set and scope, helpful code

I recently discovered BetterNestedSet and this mailing list while looking
for a simple way to manage a hierarchy of categories for a project
management solution I''m working on.  I''m very intrigued by the
new ez-set
version, since IMHO the interface is much simpler than the previous set of
methods.  I''m all in favor of making a *better* API rather than trying
to
match acts_as_tree.

One question: Does the concept of scope still apply in ez-set?  I tried
using it with multiple root nodes and no scope, and it seems to work fine,
but I''m not sure if it''s just a coincidence with how I have my
initial data
setup.  I haven''t written much code yet to move nodes around,
re-/un-root
subtrees, etc.

Also, I thought I''d share a bit of migration code that might be useful
to
others or when you go about writing a step-by-step setup guide.  It''s a
method I added to my CreateCategories migration class that makes it really
easy to create leaf nodes along with all parents up the tree:

def self.create_category (path)
  parent = nil
  path.split('':'').each do |name|
    cat = Category.find_or_create_by_name_and_parent_id(name, parent)
    parent.children << cat if !parent.nil?
    parent = cat
  end
end

I call this from my "up" method to create leaf nodes:

  create_category(''Infrastructure:Hardware:Servers'')
  create_category(''Infrastructure:Software:Windows XP'')
  ...

Seems to work, but do let me know if I''m missing some subtly of the new
API.

Thanks for the great plugin(s)!  Keep us posted on the feedback on ez-set...

Dustin

Hi Dustin,

Thanks for your comments, and we''re glad you''ve been enjoying
the plugin.
> methods.  I''m all in favor of making a *better* API rather than
trying to
> match acts_as_tree.
Actually, the ez-set branch matches the acts_as_tree API much more
closely than trunk does.
>
> One question: Does the concept of scope still apply in ez-set?
Yes. All that stuff works the same.
> def self.create_category (path)
>   parent = nil
>   path.split('':'').each do |name|
>     cat = Category.find_or_create_by_name_and_parent_id(name, parent)
>     parent.children << cat if !parent.nil?
>     parent = cat
>   end
> end
Hey, that looks neat. If you wanted to you could post it on the wiki page:
http://wiki.rubyonrails.org/rails/pages/BetterNestedSet

Cheers,
Krishna