I want to develop admin controller to do simple CRUD operations on not-so-complex models. I want it to be DRY and to allow adding features to all of them easily. This is my second attempt, the first one was way too ugly: it used inheritance from admin's base controller and descendants passed customization parameters to base class; also, have used custom "render" methods to find template for specific controller or, if the specific template is missing, fall back to general template.
And then it broke. Yeah, this could be fixed, but the whole idea seemed bad.
I just finished the second attempt and it looks promising.
First, it includes only one controller and uses routes to determine the actual model to operate on. Every route includes additional parameter that is passed to controller that contains name of model:
map.resources :users, :controller => 'items',
:requirements => { :item_type => 'User' }
map.resources :regions, :controller => 'items',
:requirements => { :item_type => 'Region' }
Second, the most troublesome was to make it work like this: I have default views in app/views/items... I wanted to have subdirectories with name of particular model that would contain overrides to default templates:
app/views/items
index.html.erb
new.html.erb
edit.html.erb
_item.html.erb
_form.html.erb
app/views/items/users
_item.html.erb
_form.html.erb
app/views/items/regions
_form.html.erb
Regions doesn't need custom 'item' partial because default one (which outputs only item.to_s) fits well.
Obviously, controller's view_paths should be manipulated to search first in concrete subfolders and then in default place. But the problem was that it always tried to prepend controller name and so find it in corresponding subfolder. It's not very nice being forced to create additional directories like this:
app/views/items
app/views/items/users/items
_item.html.erb
Well, after some digging the way to do it elegantly I found this solution:
1. Redefine controller's controller_path to return nil. After this all templates are searched in app/views/ instead of app/views/items, so it needs to be fixed, so
2. Redefine controller's view_paths to base in app/views/items.
3. Based on current item type prepend corresponding view path.
The result is as follows:
class ItemsController < ApplicationController
def self.controller_path
nil
end
self.view_paths = [ RAILS_ROOT + '/app/views/items' ]
before_filter :setup_model
# ... action code
private
def setup_model
@model = params[:item_type].constantize
prepend_view_path(RAILS_ROOT + '/app/views/items/' + params[:item_type].underscore)
end
end
Happy coding!
