Betternestedset talk - Jan 2007 - Assuring initialization of lft and rgt

I''m having trouble setting lft and rgt for root nodes.

With betternestedset, you can''t access lft and rgt, you have to use
move_to_*

But using move_to_* when lft or rgt is nil results in an exception.

"You cannot move a node if left or right is nil
/Users/roberthead/Documents/Projects/icrew_machine/config/../vendor/plugins/betternestedset/lib/better_nested_set.rb:427:in
`move_to''
/Users/roberthead/Documents/Projects/icrew_machine/config/../vendor/plugins/betternestedset/lib/better_nested_set.rb:421:in
`move_to_child_of''..."

What am I missing?

Many thanks in advance.

Robert Head
robert.head at gmail.com
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Hi Robert,

The lft and rgt values are set for new records when they are saved:

i = Item.new # lft and rgt are nil
i.save            # lft = 1, rgt = 2

if you have a table with preexisting records that don''t have lft or
rgt, you can use the SetClass.renumber_all method to get things fixed
up. (Note that if you have multiple trees, you need to make sure that
all members of each tree have the same scope value before doing this).

Cheers,
Krishna

On 1/30/07, Robert Head <robert.head at gmail.com>
wrote:
> I''m having trouble setting lft and rgt for root nodes.
>
> With betternestedset, you can''t access lft and rgt, you have to
use
> move_to_*
>
> But using move_to_* when lft or rgt is nil results in an exception.
>
> "You cannot move a node if left or right is nil
>
/Users/roberthead/Documents/Projects/icrew_machine/config/../vendor/plugins/betternestedset/lib/better_nested_set.rb:427:in
> `move_to''
>
/Users/roberthead/Documents/Projects/icrew_machine/config/../vendor/plugins/betternestedset/lib/better_nested_set.rb:421:in
> `move_to_child_of''..."
>
> What am I missing?
>
> Many thanks in advance.
>
> Robert Head
> robert.head at gmail.com
> _______________________________________________
> Betternestedset-talk mailing list
> Betternestedset-talk at rubyforge.org
> http://rubyforge.org/mailman/listinfo/betternestedset-talk
>
>
>