# Überauth Facebook
> Facebook OAuth2 strategy for Überauth.
## Installation
1. Setup your application at [Facebook Developers](https://developers.facebook.com).
1. Add `:ueberauth_facebook` to your list of dependencies in `mix.exs`:
```elixir
def deps do
[{:ueberauth_facebook, "~> 0.2"}]
end
```
1. Add the strategy to your applications:
```elixir
def application do
[applications: [:ueberauth_facebook]]
end
```
1. Add Facebook to your Überauth configuration:
```elixir
config :ueberauth, Ueberauth,
providers: [
facebook: [{Ueberauth.Strategy.Facebook, []}]
]
```
1. Update your provider configuration:
```elixir
config :ueberauth, Ueberauth.Strategy.Facebook.OAuth,
client_id: System.get_env("FACEBOOK_CLIENT_ID"),
client_secret: System.get_env("FACEBOOK_CLIENT_SECRET")
```
1. Include the Überauth plug in your controller:
```elixir
defmodule MyApp.AuthController do
use MyApp.Web, :controller
plug Ueberauth
...
end
```
1. Create the request and callback routes if you haven't already:
```elixir
scope "/auth", MyApp do
pipe_through :browser
get "/:provider", AuthController, :request
get "/:provider/callback", AuthController, :callback
end
```
1. You controller needs to implement callbacks to deal with `Ueberauth.Auth` and `Ueberauth.Failure` responses.
For an example implementation see the [Überauth Example](https://github.com/ueberauth/ueberauth_example) application.
## Calling
Depending on the configured url you can initial the request through:
/auth/facebook
Or with options:
/auth/facebook?scope=email,public_profile
By default the requested scope is "public_profile". Scope can be configured either explicitly as a `scope` query value on the request path or in your configuration:
```elixir
config :ueberauth, Ueberauth,
providers: [
facebook: {Ueberauth.Strategy.Facebook, [default_scope: "email,public_profile,user_friends"]}
]
```
Starting with Graph API version 2.4, Facebook has limited the default fields returned when fetching the user profile.
Fields can be explicitly requested using the `profile_fields` option:
```elixir
config :ueberauth, Ueberauth,
providers: [
facebook: {Ueberauth.Strategy.Facebook, [profile_fields: "name,email,first_name,last_name"]}
]
```
See [Graph API Reference > User](https://developers.facebook.com/docs/graph-api/reference/user) for full list of fields.
## License
Please see [LICENSE](https://github.com/ueberauth/ueberauth_facebook/blob/master/LICENSE) for licensing details.