Awesome nested set - how can I get a statement of any subtree?

Question

I am a newbie and I am playing with this gem. I have in database a tree structure. But now I am struggling with a way, how to get a statement of items for example on the first level... or the count items on the first or second level...

Could anyone help me please with this problem? I found at GitHub this loop for a statement of items:

Category.each_with_level(Category.root.self_and_descendants) do |category, level|
  ...
end

But I still don't know, how to use it... I'll be glad for every hint!

Thank you so much

Answer 1

You could loop through all the categories and count the items on level 1.

With in Rails console try the following:

count = 0
Category.each_with_level(Category.all) do |account, level|
    count += 1 if level == 1
end
puts count

And to print the items you could try this:

Category.each_with_level(Category.all) do |account, level|
    puts "#{level} - #{category.name}"
end