Move to namespace


I’ve built the Admin section of my project first, and would like to move it to its own Admin namespace.

I have four resources: Form, Element, Admin and User.

Old URL would be:


New URL would be:


How do I migrate from one namespace to another?

After moving I want to create a second FormsController in the default namespace.

I would then script/generate controller and script/generate view and modify as needed.

Looking forward to hear your thoughts about this.


Create a folder named "admin" in the following directories:

- app/controllers
- app/helpers
- app/views

Move the controllers, helpers and views which are to be namespaced to
the corresponding admin subdirectory.

You will need to edit the controllers that are namespaced. For

Before: class FormsController < ApplicationController
After: class Admin::FormsController < ApplicationController

And do the same with your namespaced helpers.

Lastly, modify your routes.rb to reflect the namespaced resources:

map.namespace :admin do |admin|
  admin.resources :forms
  admin.resources :elements


I think I got it all wrong. You want a fast way of refactoring from
one namespace to another?

Your first post looks like it’s exactly what I need.

Moving from Default namespace to Admin namespace is what I wanted.

But if there is a faster way, please don’t hesitate to share.

Uh oh.

500 Internal Server Error

Because I already have a Controller named AdminController, I used the namespace Backend.

I organized the files like you said in your first post. Every Controller and every Helper now looks like this:

class Backend::AdminController < ApplicationController

Any ideas?

I experimented with this line in routes.rb:

map.root :controller => :forms

instead of

map.root :controller => “forms”

That caused the 500 error.

Now that last statement is valid, but doesn’t work. How do I make the root path ‘/’ point to Backend::FormsController?

When I log in as admin, I get the error:

undefined method `form_path’ for #ActionView::Base:0x76ec1a

How do I make the *_path method understand what namespace we’re in?


You'll need to point to the path of the controller. So for your
Backend::FormsController, the root route should be set as:

map.root :controller => "backend/forms"

Since Backend::FormsController resides on backend/forms.rb

Also, the path and url helpers for your namespaced controllers are now
named backend_{controller}_path. You can confirm this - and check out
all the other routes, as well - by running:

rake routes

In one of my views I used to have the line:

<%= link_to ‘Show’, form %>

Which looked neat. According to ‘rake routes’, I should now be able to use backend_form:

backend_form GET /backend/forms/:id {:controller=>“backend/forms”, :action=>“show”}

But that gives me:

undefined local variable or method `backend_form’ for #ActionView::Base:0x19fae86

So now we have this:

<%= link_to ‘Show’, :controller=>“backend/forms”, :action=>“show” %>

Which works but is less neat.

My app/views directory looks like this:







My controllers are now layout-less. Should the layouts dir be one higher?

You'll need to append _url or _path for the url helpers to work. :wink:

Layouts are namespace agnostic. Specifying layout "backend" in your
Backend::ElementsController, for example, would load "app/views/
layouts/backend.erb" as that controller's layout.

Where do I place my layout so I don’t have to specify one explicitly?

I got this line of code:

<% form_for([:backend, @form]) do |f| %>

From here:

But still get the error

undefined method `form_path’ for #ActionView::Base:0x1f25d83

If you want all your controllers to use the same layout, you could
just define it at application.rb, like:

class ApplicationController
  layout "mylayout"

Try this form_for construct:

<% form_for @form, :url => {:action => "update"} do |f| %>

Or for new records:

<% form_for @form, :url => {:action => "create"} do |f| %>