# acts\_as\_tree error

**URL:** <https://discuss.rubyonrails.org/t/acts-as-tree-error/46238>\
**Category:** rubyonrails-talk\
**Created:** [September 21, 2009, 11:36pm UTC](https://discuss.rubyonrails.org/t/acts-as-tree-error/46238 "2009-09-21T23:36:02Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Jason14](https://avatars.discourse-cdn.com/v4/letter/j/8e8cbc/32.png) [@Jason14](https://discuss.rubyonrails.org/u/Jason14)\
**Post date:** [September 21, 2009, 11:36pm UTC](https://discuss.rubyonrails.org/t/acts-as-tree-error/46238/1 "2009-09-21T23:36:02Z")

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I am getting the following error when I attempt to use acts\_as\_tree. I am new to this relationship and am stuck.

undefined method `acts\_as\_tree'

Model class Rental \< ActiveRecord::Base &nbsp;&nbsp;acts\_as\_tree :order =\> "sort\_order"

&nbsp;&nbsp;validates\_presence\_of :name &nbsp;&nbsp;validates\_numericality\_of :sort\_order end

Schema create\_table "rentals", :force =\> true do |t| &nbsp;&nbsp;&nbsp;&nbsp;t.string "name" &nbsp;&nbsp;&nbsp;&nbsp;t.integer "sort\_order" &nbsp;&nbsp;&nbsp;&nbsp;t.integer "parent\_id" &nbsp;&nbsp;&nbsp;&nbsp;t.datetime "created\_at" &nbsp;&nbsp;&nbsp;&nbsp;t.datetime "updated\_at" &nbsp;&nbsp;end

What am I missing?

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<div class="post-metadata">

**Author:** ![Frederick\_Cheung](https://sea2.discourse-cdn.com/rubyonrails/user_avatar/discuss.rubyonrails.org/frederick_cheung/32/3901_2.png) [@Frederick\_Cheung](https://discuss.rubyonrails.org/u/Frederick_Cheung)\
**Post date:** [September 21, 2009, 11:57pm UTC](https://discuss.rubyonrails.org/t/acts-as-tree-error/46238/2 "2009-09-21T23:57:44Z")

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did you install the acts\_as\_tree plugin ?

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<div class="post-metadata">

**Author:** ![rab](https://sea2.discourse-cdn.com/rubyonrails/user_avatar/discuss.rubyonrails.org/rab/32/710_2.png) [@rab](https://discuss.rubyonrails.org/u/rab)\
**Post date:** [September 22, 2009, 12:13pm UTC](https://discuss.rubyonrails.org/t/acts-as-tree-error/46238/3 "2009-09-22T12:13:25Z")

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You have installed the acts\_as\_tree plugin, right?

&nbsp;&nbsp;&nbsp;script/plugin install acts\_as\_tree

(it's on git://github.com/rails/acts\_as\_tree.git)

-Rob

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<div class="post-metadata">

**Author:** ![Jason14](https://avatars.discourse-cdn.com/v4/letter/j/8e8cbc/32.png) [@Jason14](https://discuss.rubyonrails.org/u/Jason14)\
**Post date:** [September 25, 2009, 2:40am UTC](https://discuss.rubyonrails.org/t/acts-as-tree-error/46238/4 "2009-09-25T02:40:41Z")

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script/plugin install acts\_as\_tree (git://github.com/rails/acts\_as\_tree.git)

I didn't realize it was a plugin. The articles and book I was following led me to believe it was a native relationship.

Thanks!