Web Services on Rails

Displaying Photos from Flickr Using XML-RPC:

Flickr is primarily a photo-sharing service provided by Yahoo!, though it has recently branched out to offer other features. Basic accounts are free, and Flickr has a web service API that provides access via REST, SOAP, and XML-RPC. Because we've already covered SOAP and REST, we'll build our client using the XML-RPC architecture.

As you probably expected, you need a Flickr key before you can access their API. Since Flickr is a part of Yahoo!, you must set up a Yahoo! account first, then associate that account with the Flickr service. Start at http://www.flickr.com/signup, which walks you through the sign-up process. Once you've got your Flickr key, you're ready to start building your XML-RPC client.

To make an XML-RPC client for your Rails application you need to:

1. Create an RPC driver

2. Call the methods

3. Use the results in your Rails application

We'll demonstrate by getting the latest three images from Flickr using their interestingness.getList method. Update the code_controller.rb file from the previous examples to contain this new flickrtest method. Here is the code for our controller:

class CodeController < ApplicationController
  def flickrtest
     flickruri = "http://www.flickr.com/services/xmlrpc/"
     server = XMLRPC::Client.new2(flickruri)
     flickrkey = "YOUR FLICKR KEY"
     details = {:api_key => flickrkey, :per_page => "3"}
     result = server.call("flickr.interestingness.getList", details)
     @doc = REXML::Document.new result
   end
end

And here's the view that ...