Adding extra params to rails route resources - ruby-on-rails

Question

What I want to do seems simple, but might not be "proper"
let's say I have an image resource, and I manipulate the image based on the url. In the url I want to specify it's size and whether it's grayed, colored, or dimmed or some other condition.
currently I have a number of named routes that look like this.
map.gray_product_image "images/:product/:image/gray/:size.:format", :controller => 'images', :action => 'gray_product_image'
for me the trick is that if I created this useing Rails resources, I don't know how I would specify the :size, :format, or it's "color type".
I guess I would like to add a member route and specify my params like the following.
map.resources :products do |products|
products.resources :images, :member => {:gray_product_image => {':image/:size.:format' => :get}}
end
There are other times where I have wanted to added extra info to a resource route but didn't know how.
Any help would be greatly appreciated,
Thanks.

Answer 1

There's no good way to remove the controller/id part of a resource. The closest you're going to get through tricking ActionController with something like this:
map.resources :gray, :path_prefix => "/images/:product/:image_id/",
:controller => 'images', :requirements => {:colour => "gray"}
Which will produce routes like www.site.com/images/product/4/gray/1234.html with the following params hash:
params => {
:image_id => 4,
:id => 1234,
:colour => "gray",
:product => "product"
}
The format won't be passed explicitly but it will be available in the controller through the usually respond_to means.
Next you'll have to work some magic in controller to trick rails into doing what you want.
class ImagesController < ApplicationController
def show
#size = params[:id]
#image = Image.find(params[:image_id])
...
end
end
This actually works better as a filter so:
class ImagesController < ApplicationController
def initialize_colour
unless params[:colour].nil?
#size = params[:id]
#colour = params[:colour]
#image = Image.find(params[:image_id])
end
end
before_filter :initialize_colour, :except => [:index, :new, :create]
...
end
However to make good use of these routes, you're going to have to pass all those extra parameters to your url for calls. Like this:
gray_url(size, :image_id => #image.id, :product => product)
But helpers make that easy.
module ApplicationHelper
def easy_gray_url(image, size, product)
gray_url(size, :image_id => image.id, :product => product)
end
end

Answer 2

Check out the documentation for Resources. You'll find this:
The resources method accepts the
following options to customize the
resulting routes:
:requirements - Set custom routing parameter requirements; this is a hash of either regular expressions (which must match for the route to match) or extra parameters. For example:
map.resource :profile,
:path_prefix => ':name',
:requirements => { :name => /[a-zA-Z]+/, :extra => 'value' }
will only match if the first part is alphabetic, and will pass the parameter :extra to the controller.

Answer 3

I have realized that the way I want to represent my resources simply falls outside of the normal Rails resources, and that's ok. The problem I was really having was that each time added anther action and named route to get to what I wanted it felt wrong, I was repeating myself, both in my routes and in my actions.
I went back to simply creating my named routes, and spent a little more time in the controller so that I could keep my routes simple. Below is what I have now, and I am ok with it.
#routes.rb
map.with_options :controller => 'sketched_images', :action => 'show', :path_prefix => '/sketches', :name_prefix => 'sketched_', :color => 'grey' do |m|
m.style "styles/:style/:color/:size.:format"
m.design "designs/:design/:color/:size.:format"
m.product "products/:product/:color/:size.:format"
m.color_combo "colored_products/:color_combo/:size.:format"
end
class SketchedImagesController < ApplicationController
caches_page :show
before_filter :load_data
def show
#size = params[:size] || 100
respond_to do |wants|
wants.png
wants.jpg
end
end
private
def load_data
case
when params[:design]
#image = ClothingDesign.from_param(params[:design]).sketched_image
greyed
when params[:style]
#image = ClothingStyle.from_param(params[:style]).sketched_image
greyed
when params[:product]
#image = Product.from_param(params[:product]).sketched_images.first
greyed
when params[:color_combo]
#color_combo = ColorCombo.find_by_id(params[:color_combo])
#object = #color_combo.colorable
if #object.active? && !#object.sketched_images.blank?
#image = #object.sketched_images.first
colored
else
#image = #product.style.sketched_image
dimmed
end
end
end
def greyed
#blank = "#FFF"
#print = "#000"
#highlight = "#666"
end
def colored
#blank = "##{#color_combo.blank_color.value}"
#print = "##{#color_combo.design_color.value}"
#highlight = "##{#color_combo.highlight_color.value}" unless #color_combo.highlight_color.blank?
end
def dimmed
#blank = "#BBB"
#print = "#000"
#highlight = "#444"
end
end