Rails Routing with Query String

Question

I have a problem where I need values passed in from a GET request and I don\'t know how to set up the routing definition.

My Category object has a type(string),a col

Answer 1

One RESTful way to to do this would involve a product resource nested beneath a category resource, like so:

http://www.myapp.com/categories/toy/products?color=red

Your routes.rb would need to contain:

  map.resources :categories do |category|
    category.resources :products
  end

Since my url above using the Category's type attribute for routing, I'm implying that each type is unique, like an id. It'll mean that whenever you're loading a category in the Categories controller (or anywhere else) you'll need to load the category with Category.find_by_type(params[:id]) instead of Category.find(params[:id]). I like routing categories this way whenever possible.

Your ProductsController controller index action would find products using lines like:

  @category = Category.find_by_type(params[:category_id])
  @products = @category.products.find(:all, :conditions => { :color => params[:color]} ) 

Remember, your Category model must contain the line:

has_many :products

It's probable a good idea to enforce that in the model with validations:

validates_presence_of :type
validates_uniqueness_of :type

To make routing work you should also overwrite the to_param method in the Category model to return type instead of id:

def to_param
  self.type
end