Interfacing with a third-party API in Rails? ( Opeing URLs and Parsing XML/JSON )

for opening urls you can use open-uri

just

require 'open-uri'file_handle = open("http://google.com/blah.xml")

to parse xml you can use Nokogiri

$ gem install nokogiri

document = Nokogiri::XML(file_handle)document/"xpath/search"

very powerful library, can do all kinds of searching and modifying for both XML and HTML

same for html Nokogiri::HTML

there is also lots of JSOM support out there too

checkout Nokogiri also Hpricot is good for XML/HTML

for JSON in rails

parsed_json = ActiveSupport::JSON.decode(your_json_string)parsed_json["results"].each do |longUrl, convertedUrl|  site = Site.find_by_long_url(longUrl)  site.short_url = convertedUrl["shortUrl"]  site.saveend

see this question:How do I parse JSON with Ruby on Rails?

In a perfect world, a gem already exists for the API you want to use, and you would just use that. Otherwise, you have a few options:

• ActiveResource might make sense for you depending on the complexity of the API you want to use. For example, here's an old (and no longer functional) example of using ActiveResource to connect to the Twitter API
• Net::Http is lower-level, but certainly does the trick
• open-uri is a wrapper for net/http
• Curb uses libcurl to get things done

Parsing JSON is generally very straightforward. For XML, as stated in another answer, Nokogiri is probably the way to go.