HTTP GET and POST requests with Ruby

Nov 07, 2007

A while ago, I was working on a project for a client that used a third-party newsletter generator for capturing and storing email addresses. To add an email address, the application spits out some code for a form that you can put on your site. A user supplies his name and email address, then submits the form and it gets stored within the third-party app's database.

The problem arose when they wanted to automatically subscribe not only people who requested subscriptions, but also everyone who used the online contact form AND anyone who used the 'email to a friend' feature on one of the interior pages. Obvious misgivings aside, I set out to do what I was told (like any good drone).

The problem was, I needed to do a POST request to subscribe the person to the third-party app, but I couldn't do that with a regular form because I was already posting to the actual action being invoked. Luckily, Ruby has a built in Net::HTTP class for generating GET and POST requests from within the code.

Here is the method I needed to add the POST request to:

def email_to_friend
  ...other code...
  # now, do the dirty work
  require 'net/http'
  # get the url that we need to post to
  url = URI.parse('http://www.url.com/subscribe')
  # build the params string
  post_args1 = { 'email' => params[:email] }
  # send the request
  resp, data = Net::HTTP.post_form(url, post_args1)

The post_form method returns a Net::HTTPResponse object and an entity body string (in Ruby 1.8, it only returns the Net::HTTPResponse object). You can also use the post method.

Similarly, you can perform a GET request on a URL like so:

require 'net/http'
result = Net::HTTP.get(URI.parse('http://www.site.com/about.html'))
# or
result = Net::HTTP.get(URI.parse('http://www.site.com'), '/about.html')

The get method returns a String.

That's simple enough, right?

Tagged: railsgetposttutorial