Most of the rails apps I’ve done lately come with the requirement to include the picture (avatar) of the user that is signed in. Here is an small example of an app I delivered last week:

This problem can be solved the hard way implemnting the functionality for uploading, managing and rendering the images and associating them to the app users (and if you are using heroku, good luck with their restrictive file system), or you can delegate this problem to Gravatar. Gravatar was conceived to be the place where you put once the avatar you want to be recognized for, and any web app can use to render the user picture.

If you don’t have your gravatar, its very easy to sign up with a valid email, and manage the avatar you want to use to be recognized. Several popular services like Github uses gravatar. Once the account is created, gravatar will identify the user with the email.

To render a gravatar picture in a rails app is very easy. Just follow these steps.

• Include the gravastic gem in your Gemfile

  gem ‘gravtastic’

and run

bundle install

• Now, you need a model to represent a user in your system. Lets suppose that in our example, the user is represented by the model class User, and lets asume that this class has an attribute ‘email’ (remember that Gravatar identifies an user by his email).

  class User < ActiveRecord::Base … # Include these 2 lines include Gravtastic gravtastic … end

• To render a gravatar avatar in a page, just go to your view and use the traditional image_tag helper passing as an argument the gravatar url for the user:

  <%= image_tag @user.gravatar_url %>

And that’s it. As always, you can go directly to the source for more options offered by this gem.