Getting gravatar images with Ruby on Rails

08 June 2010 on Ruby, Tips and Tricks

What is Gravatar?

A Globally Recognized Avatar

Your Gravatar is an image that follows you from site to site appearing beside your name when you do things like commenting or posting on a blog. Avatars help to identify your posts on blogs and web forums, so why not on any site?

Understanding how to get images from Gravatar

When you sign up in gravatar, you need to register an unique e-mail, right? Gravatar uses that email address to generate an unique MD5.hexdigest key, and then, it links that key to your image file.

Let's take a look at my gravatar image url:

http://www.gravatar.com/avatar.php?gravatar_id=fc929d292323e019d5c4a353f92d5587

See? that "id" parameter is the MD5.hexdigest key generated with your email, let's try generate that in our application and check if it's the same:

Digest::MD5.hexdigest('stjhimy@gmail.com').to_s

** Result => fc929d292323e019d5c4a353f92d5587

Yeah it's the same code, so if you prefer, you can write your own tool to get the gravatar user image: just use that key that was generated and make a string with the entire URL.

Installing and using gravtastic

Install it like a gem:

gem install gravtastic

Add to your environment.rb file:

config.gem 'gravtastic', :version => '>= 2.1.0'

In your model specify that:

class User < ActiveRecord::Base
   is_gravtastic!
end

Now in your view you can use that:

<%= image_tag @user.gravatar_url %>

You can also specify some parameters:

is_gravtastic :author_email,
  :secure => true,
  :filetype => :gif,
  :size => 120

The entire documentation here http://github.com/chrislloyd/gravtastic That's all, now you can easily get avatars from Gravatar.

Ps: if you try to get your avatar on your own without gravtastic, remember to require "digest/md5" in your project.