# NoMethodError **URL:** \ **Category:** Rails\ **Created:** [March 3, 2008, 12:30am UTC](https://www.ruby-forum.com/t/nomethoderror/130748 "2008-03-03T00:30:26Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![dave](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/ee7513/32.png) [@dave](https://www.ruby-forum.com/u/dave)\ **Post date:** [March 3, 2008, 12:30am UTC](https://www.ruby-forum.com/t/nomethoderror/130748/1 "2008-03-03T00:30:26Z")
Hi I’m having a NoMethodError NoMethodError in Admin/updateController#index undefined method `find’ for #\ in the model I have def find\_subcategory(subcategory) ``` subcategory_id = self.find(:all, :conditions => [ "subcategory ``` = ?", subcategory ]) return subcategory\_id.id end in the controller I have @tags = Tag.new @category\_id = @tags.find\_category(products[i].elements[“category”].text) I don’t understand why the find method isn’t defined, isn’t find method predefined for every active record object. Any help greatly appreciated. Thanks. ---
**Author:** ![dave](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/ee7513/32.png) [@dave](https://www.ruby-forum.com/u/dave)\ **Post date:** [March 3, 2008, 4:41am UTC](https://www.ruby-forum.com/t/nomethoderror/130748/2 "2008-03-03T04:41:19Z")
The model looks like this class Tag \< ActiveRecord::Base has\_and\_belongs\_to\_many :products, :join\_table =\> ‘products\_tags’ validates\_presence\_of :name validates\_uniqueness\_of :name acts\_as\_tree :order =\> ‘-rank DESC’ def find\_category(category) # if tag for given category exists return the id, else create it and return id category\_id = self.find(:all, :conditions =\> [ “category = ?”, category ]) if category\_id then return category\_id.id else new\_category = self.new new\_category.name = category new\_category.save category\_id = self.find(:all, :conditions =\> [“category = ?”, category]) return category\_id.id end end def find\_subcategory(subcategory) ``` # if tag for given subcategory exists return the id, else create it ``` and return id ``` subcategory_id = self.find(:all, :conditions => [ "subcategory ``` = ?", subcategory ]) if subcategory\_id then return subcategory\_id.id else new\_subcategory = self.new new\_subcategory.name = subcategory new\_subcategory.save subcategory\_id = self.find(:all, :conditions =\> [“subcategory = ?”, subcategory]) return subcategory\_id.id end end end products[i].elements[“category”].text Comes from an xml file, that I’m importing, I’m doing a find to see if the category already exists in the database before I insert the product so that I can link the product with an appropriate category, and subcategory. ---
**Author:** ![dave](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/ee7513/32.png) [@dave](https://www.ruby-forum.com/u/dave)\ **Post date:** [March 3, 2008, 4:28am UTC](https://www.ruby-forum.com/t/nomethoderror/130748/3 "2008-03-03T04:28:22Z")
By the looks of things, Tag is inherting correctly from ActiveRecord::Base, but could you show us your whole model anyway? There’s find\_category missing from what you gave us and I’m sure that: products[i].elements[“category”].text could be done much more nicer if I knew what you were trying to do! I think you’re iterating through the products, finding the category for each and then the text for that category and then doing a find on it. I don’t fully understand why you’re doing the find if you already know what the category is! On Mon, Mar 3, 2008 at 9:59 AM, Dave [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > in the model I have > > Thanks. > > > – Ryan B. > **[frozenplague.net](http://www.frozenplague.net)** > > This domain may be for sale! Feel free to add me to MSN and/or GTalk as this email. ---
**Author:** ![dave](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/ee7513/32.png) [@dave](https://www.ruby-forum.com/u/dave)\ **Post date:** [March 3, 2008, 10:38am UTC](https://www.ruby-forum.com/t/nomethoderror/130748/4 "2008-03-03T10:38:17Z")
On 3 Mar 2008, at 03:40, Dave wrote: > acts\_as\_tree :order =\> ‘-rank DESC’ > > def find\_category(category) > > # if tag for given category exists return the id, else create it and > > return id > category\_id = self.find(:all, :conditions =\> [ “category = ?”, > category ]) find is a class method, not an instance method. from an instance method you have to say Tag.find or self.class.find. However, what I think you want to do here is make the find\_category method a class method. Fred ---
**Author:** ![dave](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/ee7513/32.png) [@dave](https://www.ruby-forum.com/u/dave)\ **Post date:** [March 4, 2008, 4:04am UTC](https://www.ruby-forum.com/t/nomethoderror/130748/5 "2008-03-04T04:04:04Z")
If you wanted to use “find\_category” as a method of Model “Tag”, then you must also define your method as such: ``` def self.find_subcategory(subcategory) subcategory_id = self.find(:all, :conditions => ``` [“subcategory= ?”, subcategory]) return subcategory\_id.id end I just put “self.” infront of the method name. ---
**Author:** ![dave](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/ee7513/32.png) [@dave](https://www.ruby-forum.com/u/dave)\ **Post date:** [March 4, 2008, 6:26am UTC](https://www.ruby-forum.com/t/nomethoderror/130748/6 "2008-03-04T06:26:28Z")
Thanks for the help, I’ll see if I can get this working when I get a chance later on, however this does make sense. ---
**Author:** ![dave](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/ee7513/32.png) [@dave](https://www.ruby-forum.com/u/dave)\ **Post date:** [March 3, 2008, 10:59am UTC](https://www.ruby-forum.com/t/nomethoderror/130748/7 "2008-03-03T10:59:00Z")
Ahh good pick Fred! On Mon, Mar 3, 2008 at 8:07 PM, Frederick C. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > > has\_and\_belongs\_to\_many :products, > > category\_id = self.find(:all, :conditions =\> [ “category = ?”, > > if category\_id then > > end > > if subcategory\_id then > > > > > > > > – Ryan B. > **[frozenplague.net](http://www.frozenplague.net)** > > This domain may be for sale! Feel free to add me to MSN and/or GTalk as this email.