Pragmatic Authentication Library: Facebook workflows

Collection of Facebook workflows for PAL.

1. Facebook Login (OAuth2 Authorization Code Grant) workflow

For details, read the Facebook documentation.

Options

You can configure the workflow by passing options below into pal:new/2 or pal:group/2 functions:

• client_id (required) - The client ID obtained from the App dashboard.
• client_secret (required) - The client secret obtained from the App Dashboard.
• redirect_uri (required) - The client redirection endpoint. After completing its interaction with the resource owner, the authorization server directs the resource owner's user-agent to this uri.
• scope (optional) - A list of requested permissions.
• request_options (optional) - Options for the hackney HTTP client.
• includes (optional) - Parts of authentication schema to be processed by the workflow. All by default, [uid, credentials, info, extra, rules].

Input Data

• code - The authorization code.
• state - The state was previously passed to the authentication provider.
• error If the request fails due to a missing, invalid, or mismatching redirection URI, or if the client identifier is missing or invalid.

Authentication Schema

An successful execution of pal:authenticate/{2,3} function returns the authentication schema below.

#{access_token => <<"...">>,
  expires_in => <<"5183998">>}

See a complete example with PAL and Cowboy HTTP server here.

2. Facebook User (user's profile data) workflow

Options

You can configure the workflow by passing options below into pal:new/2 or pal:group/2 functions:

• request_options (optional) - Options for the hackney HTTP client.
• includes (optional) - Parts of authentication schema to be processed by the workflow. All by default, [uid, credentials, info, extra, rules].

Input Data

• access_token - An access Token obtained using the pal_facebook_oauth2_authcode workflow.

Authentication Schema

An successful execution of pal:authenticate/{2,3} function returns the authentication schema below.

#{uid => <<"...">>,
  info =>
    #{name => <<"John Doe">>,
      first_name => <<"John">>,
      last_name => <<"Doe">>,
      gender => <<"male">>,
      email => <<"john@example.com">>,
      image => <<"https://graph.facebook.com/...">>,
      uri => <<"https://www.facebook.com/...">>}}

See a complete example with PAL and Cowboy HTTP server here.

License

The source code is provided under the terms of the MIT license.