error when following Agile Web Development in RoR

I was originally using instant rails, and decided to try installing ruby, rails, and mysql on my own. No problem with the install. I used gem install rails --include-dependencies, and got no errors. The problem seems to be with defining the scaffold method. I had no problems with this in Instant Rails, and i’m guessing this has something to do with Rails 2.0. Would the RoR gurus please lend a hand, and guide me to the light?



NoMethodError in AdminController#index

undefined method `scaffold’ for AdminController:Class

RAILS_ROOT: /Users/jason/rails/depot

Application Trace | Framework Trace | Full Trace


Yep, dynamic scaffolding has been moved out to a plugin in Rails 2.0.

Your options are:

1) Switch to rails 1.2.6. This will be the easiest route if you're still learning rails using AWDWR 2nd ed. 2) Install the scaffolding plugin with:       script/plugin install scaffolding

Option 1 means you are continuing to tread on the same turf expected by the book, Option 2 is but on step towards adapting your knowledge, and the books, to Rails 2.0.

I too had the AWDwR book 2nd Edition, P3.0 printing (use the P2.0 errata says Dave). I installed the scaffolding plugin. That step alone, didn't help, although it may have been best to delete the depot folder and start again. But that plugin may have been a different type of scaffolding.

I went back to rails version 1.2.5, that was installed when I first set up Ruby on Linix Fedora 7. I used the commands from a later post (Jan 1, by Jos Achten, step 3). In fact I had 1.2.5, and 2.0.2 installed and it asked me which I wanted to uninstall. In the end I uninstalled both and asked for "--version 1.2.5 --include- dependencies" and that did it. Then I had to delete the depot folder and restart from the beginning of that chapter. Everything worked as on pages 68 onward. Frankly, I'm impressed that it generated so much automatically.

Thank you for asking the questions, and thank you for all the replies!

I just ran into the same issue and had it resolved in no time flat thanks to you!


1. I had installed Rails according to the Windows recommendation in the book 2. When I ran into the problem, I googled the error message, found this error message, and did the following: 3. typed "gem uninstall rails" at the rails command line 4. typed "gem install rails --version 1.2.6 --include-dependencies" at the rails command line 5. delete or rename the original depot folder 6. do the following to quickly get back to where you were when the error hit you: D:\Rails\rails_apps\work>rails depot cd depot D:\Rails\rails_apps\work\depot>ruby script/generate model product edit D:\Rails\rails_apps\work\depot\db\migrate\001_create_products.rb   add       t.column :title, :string       t.column :text, :text       t.column :image_url, :string rake db:migrate ruby script/generate controller admin edit D:\Rails\rails_apps\work\depot\app\controllers \admin_controller.rb   add      scaffold :product

(change D:\Rails to where you installed rails, obviously)

Thanks, Werner

Just a quick correction to the last entry. When editing the migration for the products model, the line 't.column :text, :text' should be 't.column :description, :text'. My validation kept failing until I realized that the 'description' column had been incorrectly named as 'text'.


If you're following the AWDWR book using Rails 2 you will hit other problems - for example when it talks about pagination that has been removed from Rails 2 so it won't work as expected. While running through the Depot for learning I'd stick with 1.2.6 and then start develping on 1.2.6 so you can rely on the book. Only make the change to 2.0 when you're comfortable with the basics.

You can install "classic pagination" if that's an issue.

On the topic of scaffolding--I've found this helpful:

I tried installing the scaffolding plugin as suggested, and now I get the following error:

undefined method `paginate' for #<AdminController:0x3216af8> RAILS_ROOT: C:/InstantRails-2.0-win/rails_apps/depot

Do I need another plugin?

Thanks, Jeff

I originally got the <b>undefined method `scaffold' for AdminController:Class</b> then after installing pagination I got <b>undefined method `paginate' for #<AdminController:...</b>

How I got around was this: 1) check all installed gems on your machine <b>gem list --local </b> check the rails versions installed (in my case, this was 2.0.2, 1.2.6, 1.2.5, 1.2.3)

2) uninstall version 2.0.2, using this command: <b>sudo gem uninstall -v=2.0.2 rails</b>

I admit, I'm a Rails noob and have been following the instructions in AWDwR edition *3*, they haven't mentioned lack of support for this, so you kind of get stuck on page 76. Is it worth rolling back my version of rails do you think, or is scaffolding something I can live/learn without ...

cheers Tim

Scaffolding is definitely something you can live and learn without.

Is there any place where it is summarized the changes to make to Awdwr's depot exercise if we decide to use RoR 2.0? It doesn't make sens to me to learn an old technology when I'm not gonna stick with it anyways...


Yep - get the third edition ( currently in Beta )

HTH - Dave