"Net::Facebook::Oauth->new( %args )"

Returns a new object to handle user authentication. Pass arguments as a hash. The following arguments are REQUIRED unless you're passing an access_token (see optional arguments below):

• "application_id"

  Your application id as you get from facebook developers platform when you register your application

• "application_secret"

  Your application secret id as you get from facebook developers platform when you register your application

The following arguments are OPTIONAL:

• "access_token"

  If you want to instantiate an object to an existing access token, you may do so by passing it to this argument.

• "browser"

  The user agent that will handle requests to Facebook's API. Defaults to LWP::UserAgent, but can be any method that implements the methods "get", "post" and "delete" and whose response to such methods implements "is_success" and "content".

• "display"

  See "display" under the "get_authorization_url" method below.

• "api_version"

  Use this to replace the API version on all endpoints. The default value is 'v4.0'. Note that defining an api_version parameter together with "authorize_url", "access_token_url" or "debug_token_url" is a fatal error.

• "authorize_url"

  Overrides the default (4.0) API endpoint for Facebook's oauth. Used mostly for testing new versions.

• "access_token_url"

  Overrides the default (4.0) API endpoint for Facebook's access token. Used mostly for testing new versions.

• "debug_token_url"

  Overrides the default (4.0) API endpoint for Facebook's token information. Used mostly for testing new versions.

"$fb->get_authorization_url( %args )"

Returns an authorization URL for your application. Once you receive this URL, redirect your user there in order to authorize your application.

The following argument is REQUIRED:

•

"callback"

    callback => 'http://example.com/login/facebook/success'
    

The callback URL, where Facebook will send users after they authorize your application. YOU MUST CONFIRM THIS URL ON FACEBOOK'S APP DASHBOARD.

To do that, go to the App Dashboard, click Facebook Login in the right-hand menu, and check the Valid OAuth redirect URIs in the Client OAuth Settings section.

This method also accepts the following OPTIONAL arguments:

• "scope"

      scope => ['user_birthday','user_friends', ...]
      

  Array of Extended permissions as described by the Facebook Oauth API. You can get more information about scope/Extended Permission from

  <https://developers.facebook.com/docs/facebook-login/permissions/>

  Please note that requesting information other than "name", "email" and "profile_picture" will require your app to be reviewed by Facebook!

• "state"

      state => '123456abcde'
      

  An arbitrary unique string provided by you to guard against Cross-site Request Forgery. This value will be returned to you by Facebook, unchanged. Note that, as of Facebook API v3.0, this argument is mandatory, so if you don't provide a 'state' argument, we will default to "time()".

• "auth_type"

  When a user declines a given permission, you must reauthorize them. But when you do so, any previously declined permissions will not be asked again by Facebook. Set this argument to 'rerequest' to explicitly tell the dialog you're re-asking for a declined permission.

• "display"

      display => 'page'
      

  How to display Facebook Authorization page. Defaults to "page". Can be any of the following:

•

"response_type"

    response_type => 'code'
    

When the redirect back to the app occurs, determines whether the response data is in URL parameters or fragments. Defaults to "code", which is Facebook's default and useful for cases where the server handles the token (which is most likely why you are using this module), but can be also be "token", "code%20token", or "granted_scopes". Note that changing this to anything other than 'code' might change the login flow described in this documentation, rendering calls to "get_access_token()" pointless. Please see Facebook's login documentation <https://developers.facebook.com/docs/facebook-login/manually-build-a-login-flow> for more information.

"$fb->get_access_token( %args )"

This method issues a GET request to Facebook's API to retrieve the access token string for the specified code (passed as an argument).

Returns the access token string or raises an exception in case of errors (make sure to trap calls with eval blocks or a try/catch module). Note that Facebook's access tokens are short-lived, around 2h of idle time before expiring. If you want to "upgrade" the token to a long lived one (with around 60 days of idle time), use this token to feed the "get_long_lived_token()" method.

You should call this method inside the route for the callback URI defined in the "get_authorization_url" method. It receives the following arguments:

•

"code"

This is the verifier code that Facebook sends back to your callback URL once user authorize your app, you need to capture this code and pass to this method in order to get the access token.

Verifier code will be presented with your callback URL as code parameter as the following:

http://your-call-back-url.com?code=234er7y6fdgjdssgfsd...

Note that if you have fiddled with the "response_type" argument, you might not get this parameter properly.

When the access token is returned you need to save it in a secure place in order to use it later in your application. The token indicates that a user has authorized your site/app, meaning you can associate that token to that user and issue API requests to Facebook on their behalf.

To know WHICH user has granted you the authorization (e.g. when building a login system to associate that token with a unique user on your database), you must make a request to fetch Facebook's own unique identifier for that user, and then associate your own user's unique id to Facebook's.

This was usually done by making a GET request to the "me" API endpoint and looking for the 'id' field. However, Facebook has introduced a new endpoint for that flow that returns the id (this time as 'user_id') and some extra validation data, like whether the token is valid, to which app it refers to, what scopes the user agreed to, etc, so now you are encouraged to call the "debug_token()" method as shown in the SYNOPSIS.

IMPORTANT: Expect that the length of all access token types will change over time as Facebook makes changes to what is stored in them and how they are encoded. You can expect that they will grow and shrink over time. Please use a variable length data type without a specific maximum size to store access tokens.

"$fb->get_long_lived_token( access_token => $access_token )"

Asks facebook to retrieve the long-lived (~60d) version of the provided short-lived (~2h) access token retrieved from "get_access_token()". If successful, this method will return the long-lived token, which you can use to replace the short-lived one. Otherwise, it croaks with an error message, in which case you can continue to use the short-lived version.

See here <https://developers.facebook.com/docs/facebook-login/access-tokens/refreshing> for the gory details.

"$fb->debug_token( input => $access_token )"

This method should be called right after "get_access_token()". It will query Facebook for details about the given access token and validate that it was indeed granted to your app (and not someone else's).

It requires a single argument, "input", containing the access code obtained from calling "get_access_token".

It croaks on HTTP/connection/Facebook errors, returns nothing if for whatever reason the response is invalid without errors (e.g. no app_id and no user_id), and also if the returned app_id is not the same as your own application_id (pass a true value to "skip_check" to skip this validation).

If all goes well, it returns a hashref with the JSON structure returned by Facebook.

"$fb->get( $url, $args )"

Sends a GET request to Facebook and stores the response in the given object.

• "url"

  Facebook Graph API URL as string. You must provide the full URL.

• $args

  hashref of parameters to be sent with graph API URL if required.

You can access the response using the following methods:

• "$response>as_json"

  Returns response as json object

• "$response>as_hash"

  Returns response as perl hashref

For more information about facebook graph API, please check http://developers.facebook.com/docs/api

"$fb->post( $url, $args )"

Send a POST request to Facebook and stores the response in the given object. See the "as_hash" and "as_json" methods above for how to retrieve the response.

• "url"

  Facebook Graph API URL as string

• $args

  hashref of parameters to be sent with graph API URL

For more information about facebook graph API, please check <http://developers.facebook.com/docs/api>

"$fb->delete( $url, $args )"

Send a DELETE request to Facebook and stores the response in the given object. See the "as_hash" and "as_json" methods above for how to retrieve the response.

• "url"

  Facebook Graph API URL as string

• $args

  hashref of parameters to be sent with graph API URL