This post originated from an RSS feed registered with Ruby Buzz by rwdaigle. Original Post: What's New in Edge Rails: Nested Resource RESTful URL Builder Feed Title: Ryan's Scraps Feed URL: http://feeds.feedburner.com/RyansScraps Feed Description: Ryan Daigle's various technically inclined rants along w/ the "What's new in Edge Rails" series. Latest Ruby Buzz Posts Latest Ruby Buzz Posts by rwdaigle Latest Posts From Ryan's Scraps

The march to RESTful nirvana continues with a drop dead easy way to build nested resource URLs. Let’s review.

Assuming the following routing configuration:

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map.resources :categories do |categories|
  categories.resources :articles
end

This automatically builds a category_url(category) and category_article_url(category, article) helper (among others) that will build the appropriate URLs:

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category_url(@category) #=> /categories/1
category_article_url(@category, @article) #=> /categories/1/article/1

All right, that’s great. But why should we have to spell out these lengthy helper method calls when it’s clear that the first argument is a Category and the second is an Article? Can’t the appropriate helper method be implied by the types of these arguments? Yes – they can, and now they are with the new url_for update. Now you can pass in a collection of models to url_for, in order of nesting (root to child), and get the correct URL:

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url_for(@category) #=> /categories/1
url_for([@category, @article]) #=> /categories/1/article/1

You can always fall back to the named routes provided for you by RESTful routing, but you now have an option to build URLs with an implied resource nesting.

tags: ruby, rubyonrails, REST