Odtnhj

I am using Rails 5.1.6

I have a model called Taxon using acts_as_nested_set. I have 4 levels of Taxons, the last level sub_category has an attribute holding names of all parents, I want to update the sub_category attribute every time any of its parents name is changed, when using after_save callback it runs into SystemStackError as each after save callback is run for each child leading to infinite loop. Any idea how to overcome this issue?

class Taxon
 acts_as_nested_set dependent: :destroy

 def update_tree_name
 if shop_sub_category?
 update(display_tree_name: beautiful_name)
 else 
 related_sub_categories = tree_list.select 
 related_sub_categories.each do |t|
 t.update(display_tree_name: t.beautiful_name)
 end
 end
end


def beautiful_name
 "#parent.parent.parent.name -> #parent.parent.name -> #parent.name-> #name"
end

I have a solution that will work for you but I do not think it is an elegant one but here you go and then you can fine tune it:

In your model:

class Taxon < ActiveRecord::Base
 cattr_accessor :skip_callbacks
 after_save :update_tree_name, :unless => :skip_callbacks
end

def update_tree_name
 if shop_sub_category?
 update(display_tree_name: beautiful_name)
 else 
 related_sub_categories = tree_list.select 
 Taxon.skip_callbacks = true # disable the after_save callback so that you do not end up in infinite loop (stackoverflow)
 related_sub_categories.each do |t|
 t.update(display_tree_name: t.beautiful_name)
 end
 Taxon.skip_callbacks = false # enable callbacks again when you finish
 end
end