# Acts\_as\_ordered\_tree **URL:** \ **Category:** Rails\ **Created:** [April 30, 2006, 6:02pm UTC](https://www.ruby-forum.com/t/acts-as-ordered-tree/59181 "2006-04-30T18:02:24Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![tvollmer](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/c68b51/32.png) [@tvollmer](https://www.ruby-forum.com/u/tvollmer)\ **Post date:** [April 30, 2006, 6:02pm UTC](https://www.ruby-forum.com/t/acts-as-ordered-tree/59181/1 "2006-04-30T18:02:24Z")
I need an ordered (sortable tree) and I just was thinking if somehting like this is possible: class Item\< ActiveRecord::Base acts\_as\_tree :order =\> “position” acts\_as\_list :scope =\> ‘parent\_id = #{self.id}’ end For my understanding mixing of two acts\_as should be póssible, at least in this case, right? Unfortunatly the :scope is not working, I am not sure how to write the scope so that only items are treated as list whos parent\_id is like mine. I tried: ‘parent\_id = #{self.id}’ ‘parent\_id = #{id}’ But I always get empty SQL statements like: ORDER BY position DESC LIMIT 1’ at line 1: SELECT \* FROM ideas WHERE (parent\_id = ) ORDER BY position DESC LIMIT Is it possible as I try or do I have to write my own acts\_as\_sortable\_tree? Regards Till ---
**Author:** ![tvollmer](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/c68b51/32.png) [@tvollmer](https://www.ruby-forum.com/u/tvollmer)\ **Post date:** [May 10, 2006, 6:17pm UTC](https://www.ruby-forum.com/t/acts-as-ordered-tree/59181/2 "2006-05-10T18:17:52Z")
Till V. wrote: > I need an ordered (sortable tree) and I just was thinking if somehting > like this is possible: > > class Item\< ActiveRecord::Base > acts\_as\_tree :order =\> “position” > acts\_as\_list :scope =\> ‘parent\_id = #{self.id}’ > end I think you’d better use acts\_as\_nested\_set. I ehanced it in a plug in, contact me ito have it. ---
**Author:** ![tvollmer](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/c68b51/32.png) [@tvollmer](https://www.ruby-forum.com/u/tvollmer)\ **Post date:** [May 10, 2006, 6:34pm UTC](https://www.ruby-forum.com/t/acts-as-ordered-tree/59181/3 "2006-05-10T18:34:08Z")
Till V. wrote: > I need an ordered (sortable tree) and I just was thinking if somehting > like this is possible: > > class Item\< ActiveRecord::Base > acts\_as\_tree :order =\> “position” > acts\_as\_list :scope =\> ‘parent\_id = #{self.id}’ > end > > For my understanding mixing of two acts\_as should be póssible, at least > in this case, right? > > Unfortunatly the :scope is not working, I am not sure how to write the > scope so that only items are treated as list whos parent\_id is like > mine. > I tried: > ‘parent\_id = #{self.id}’ > ‘parent\_id = #{id}’ > > But I always get empty SQL statements like: > > ORDER BY position DESC LIMIT 1’ at line 1: SELECT \* FROM ideas WHERE > (parent\_id = ) ORDER BY position DESC LIMIT > > Is it possible as I try or do I have to write my own > acts\_as\_sortable\_tree? > > Regards > Till did you try: class Item\< ActiveRecord::Base acts\_as\_tree :order =\> “position” acts\_as\_list :scope =\> “parent\_id” end ---
**Author:** ![tvollmer](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/c68b51/32.png) [@tvollmer](https://www.ruby-forum.com/u/tvollmer)\ **Post date:** [May 10, 2006, 7:17pm UTC](https://www.ruby-forum.com/t/acts-as-ordered-tree/59181/4 "2006-05-10T19:17:08Z")
Yes, this works great for me… class Page \< ActiveRecord::Base acts\_as\_tree :order =\> :position acts\_as\_list :scope =\> :parent\_id end This assumes that you have a “parent\_id” and “position” column in your “pages” table. You can then use the dot notation to select a page’s parent, root, siblings or childs such as… page = Page.find(123) page.parent.id page.root.id page.children.first.id AND, if you do a page.destroy … all of its sub-nodes get destroyed too. … that covers the functionality of the acts\_as\_tree but now you also get the flexibility of the acts\_as\_list… page.move\_higher page.move\_lower page.move\_to\_bottom page.move\_to\_top and because your scope is the model’s very own “parent\_id” … your ‘list’ will be confined within each parent\_id and won’t mess with the rest of the table. What I haven’t figured out is an elegant way to say “get all root nodes (parent ID of 0)” and maintain their “position”. I found some .find\_by\_parent\_id(nil) function somewhere but it didn’t work (and I can’t re-find it to show you the reference). If anybody has a suggestion other than: @nodes = Page.find(:all, :conditions =\> “parent\_id = 0”, :order =\> “position asc”) AND, If anybody would know how to implement this in Rails, please do share! [http://script.aculo.us/playground/test/functional/sortable\_tree\_test.html](http://script.aculo.us/playground/test/functional/sortable_tree_test.html) – Jeff ---
**Author:** ![tvollmer](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/c68b51/32.png) [@tvollmer](https://www.ruby-forum.com/u/tvollmer)\ **Post date:** [February 20, 2007, 4:57pm UTC](https://www.ruby-forum.com/t/acts-as-ordered-tree/59181/5 "2007-02-20T16:57:42Z")
Jeff W. wrote: > What I haven’t figured out is an elegant way to say “get all root nodes > (parent ID of 0)” and maintain their “position”. I found some > .find\_by\_parent\_id(nil) function somewhere but it didn’t work (and I > can’t > re-find it to show you the reference). > > If anybody has a suggestion other than: > > @nodes = Page.find(:all, > :conditions =\> “parent\_id = 0”, > :order =\> “position asc”) > > AND, If anybody would know how to implement this in Rails, please do > share! > > [http://script.aculo.us/playground/test/functional/sortable\_tree\_test.html](http://script.aculo.us/playground/test/functional/sortable_tree_test.html) > > – > > Jeff Here you go 🙂 [http://www.agilewebdevelopment.com/plugins/acts\_as\_ordered\_tree](http://www.agilewebdevelopment.com/plugins/acts_as_ordered_tree) - Brian