Getting started consuming web services in a Ruby on Rails 3 application

Question

So I'm getting started learning Rails. Now that Rails 3 is out, I want to stick to learning the Rails 3 way of doing things. One of the things I want to learn how to do is how to consume web services / work with third party REST APIs / create "mashup" applications. I've only done minimal work like this with PHP and pre-built libraries.

Can someone please lead me to some resources, best practices, or give me a quick 101 lesson on how to start working with these types of APIs? What gems should I use? Some sample code to get me started would be much appreciated.

Update: I am specifically trying to use the Google Books API (non-authenticated). Since there is no client library for this API, I'm wondering how other Ruby/Rails developers are working with APIs that don't come with their own Ruby library. That's why I'm looking for a more generic solution to working with "fill in the blank" API.

Update: After some research, I noticed the Net::HTTP library. All the tutorials that talked about it were fairly old. Is this still the best library to use for consuming RESTful web services? Or is there a newer Gem that makes this easier? I just want to know which gem/library I should use, and how to work with the XML/JSON result that is returned.

Update: This presentation was really helpful. It mentions a bunch of different libraries and shows examples of some of the libraries mentioned below: http://www.slideshare.net/pengwynn/json-and-the-apinauts

Answer 1

You find a lot of resources on http://github.com. SOAP sucks, as far as I heard. Cool guys use REST. Screw best practices. And I recommend you the DataMapper gem over ActiveRecord. You find a lot of sample code on github too.

Answer 2

I'd recommend REST with Nokogiri: http://railscasts.com/episodes/190-screen-scraping-with-nokogiri Nokogiri works well with xml too, not just HTML.

Answer 3

I'm a pretty big fan of HTTParty.

It's an abstraction layer on top of Net::HTTP with a nice little DSL for consuming web services. Here's a good example how easy it is to use.

It's not without some warts (lots of dependencies) but it's really the way to go if you're on the consuming side.

Answer 4

Weary is a really neat DSL for consuming RESTful services.

Clearly inspired by HTTParty but a bit newer and a bit more concise.