## How To: Authlogic to Devise

### Step 1: Migration
1. `bin/rails g migration AuthlogicToDevise`
2. (see the file below for the actual migration, `authlogic_to_devise.rb`)
3. `bin/rake db:migrate`

### Step 2: Update Gemfile
1. `gem "devise", "~> 2.2.0"`
2. `bundle install`

### Step 3: Install Devise
1. `bin/rails g devise:install`
2. (follow on-screen instructions, if any)
3. To install Devise views for overriding: `bin/rails g devise:views`

### Step 4: Update Code
1. Replace any `login_required` filters with `authenticate_user!`
2. If you define your own `current_user` methods, remove them so we are using the helpers provided by Devise (old helpers are often in `lib/authenticated_system.rb`)

### Step 5: Setup Devise Model
1. `bin/rails g devise User` (note that your model might be different than `User`)
2. IMPORTANT: remove the created migration, we manually migrated the DB above
3. Modify any of the inserted devise commands in your model, as desired

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## Tips / Troubleshooting

### Keeping Existing `UserSessionsController`

To avoid having to create new views and use the Devise controllers, you can re-use the existing `UserSessionsController` pretty easily. I found that the `devise_for :users` wasn't enough, the route wasn't loading properly; so, tell `devise_for` which controller to use:

`devise_for :users, :controllers => { :sessions => "user_sessions" }`

Then just update your form to use `@user` instead of `@user_session`. Additionally, you need to modify `UserSessionsController` slightly:

1. Delete all of the actions (`new`, `create`, `destroy`)
2. Inherit from `Devise::SessionsController` (this will provide the devise actions)
3. May need to add an entry into `config/locales/devise.en.yml` (for `en.devise.user_sessions.user.[signed_in|signed_out]`)

### Ensure Existing User Passwords Still Work

Rather than have everyone create new passwords, Devise can support Authlogic's encryption scheme. There are a few steps needed to make this work:

1. Relies on the `encryptable` gem, so add this to your Gemfile: `gem "devise-encryptable"`
2. `bundle install`
3. Tell Devise to use the Authlogic schem by opening `config/initializers/devise.rb` and setting `config.encryptor = :authlogic_sha512`
4. You also have to increase the stretches from 10 to at least 20 to match Authlogic's scheme, otherwise this won't work. So in the same file as the step above, find the `config.stretches` line and change it from 10 to 20 (keep it as 1 for test environment for performance purposes).
5. Finally, in your `User` model, you have to tell Devise to use this extension via: `devise :encryptable, ...`
6. Restart your server and your existing accounts should still work.

### FIX: "undefined method `urlsafe_base64' for SecureRandom"

If you come across this error, it's most likely because you're running Ruby 1.8.7 instead of 1.9 (that method doesn't exist in 1.8.7). But, the good thing is it's not required, we can use `hex` to replace it.

1. Create a file in `config/initializers` (mine is called `secure_random_overrides.rb`)
2. See the code below in the file called `secure_random_overrides.rb` 

### Sign In/Out Routing

It's possible that some of your login/logout routes and helpers will be screwed up. Just making note that those will likely need updated, specifically:

* `logout_path` => `destroy_user_session_path`

In addition to this, I've also had to specify a `:user` scope so the routes match up:

    devise_scope :user do
      get "/users/sign_out", :to => "user_sessions#destroy"
    end

(Note: sometimes just `get "/sign_out", ...` is enough)

It's also possible that you may need to specify the logout HTTP method in the devise config (defaults to `:delete`). I changed this to `:get`:

* `config.sign_out_via = :get`