Empower

Empower is a pre-configured OmniAuth solution for Ruby on Rails applications. In contrast to something flexible, like OmniAuth, Empower aims to create the solution simply, quickly, and effectively.

Empower currently supports the following strategies:

• Facebook
• Google (OAuth2)
• Twitter

To make this happen, you need to understand what's required from you prior to using this gem. See below.

Add this line to your application's Gemfile:

gem 'empower'

And then execute:

$ bundle

Or install it yourself as:

$ gem install empower

There are three major prerequisites to using Empower:

• Using/installing Devise
• Creating a User model
• Add name and image to your User model

Referencing this section in Devise's README, this means you should run the following commands:

$ bundle exec rails g devise:install
$ bundle exec rails g devise User

Meanwhile, the empower:install generator will take care of adding the migration for the added columns. Just double check it.

Once Devise is setup and Empower is installed, you can run its generator:

$ bundle exec rails g empower:install

Before you begin, replace the APP_ID and APP_SECRET in config/initializers/devise.rb for each of the strategies you wish to use. If you don't want to use a strategy, delete it from the Devise config file.

Note: I suggest NOT tracking these keys with Git and hiding them someone like an environment variable or a private settings file.

Restart your server and you're ready to go.

There is a helper for a sign in button for each of the strategies in the form of [strategy]_login_button. Facebook's looks like this:

<%= facebook_login_button %>

Optionally, you can pass a custom message to the button helper:

<%= facebook_login_button "Sign In, Friendo!" %>

Otherwise, if you want to handle your own links, they would look like this:

<%= link_to 'Login', user_omniauth_authorize_path(:facebook) %>

The odd man out here is Google, which needs to be written like this:

<%= link_to 'Login', user_omniauth_authorize_path(:google_oauth2) %>

When you are signed in successfully through Facebook, Empower uses Devise's after_sign_in_path_for method. You can customize this method in your application controller

[See this doc page](https://github.com/plataformatec/devise/wiki/How-To :-redirect-to-a -specific-page-on-successful-sign-in#redirect-back-to-current- page-after-oauth- signin) for more information.

There are a handful of quirks in this gem, but I think there are two worthy of noting over any others

Each individual user needs a unique email address with Devise, which makes perfect sense. A common issue with OmniAuth is that users signed up for the various services with different email addresses over the years.

The ways in which I've seen developers circumvent this is convoluted. I like to keep things simple and so we say if a social account uses a different email address, then the user account within your app is a different account.

That being said, we do consolidate accounts where we can. If, for example, your Facebook and Google accounts use the same email address, the user account within your app with be the same.

Twitter, in all its infinite wisdom, will not share email addresses in their OmniAuth solution. So, we have to create a separate form when the user signs in so we can capture a real email address.

This solution has several holes in it. There isn't a simple way of ensuring that they are entering a valid email address or an email address of someone already using the app.

If this is a concern, I suggest opening a PR to force confirmable on Devise and working it into this solution.

1. Fork it ( https://github.com/[my-github-username]/empower/fork )
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create a new Pull Request