/**
* Retrieves Facebook access token.
*
* @since 0.4
*/
public function get_fb_access_token()
{
$access_token = null;
if (isset($this->fb_sdk)) {
try {
$helper = $this->fb_sdk->getRedirectLoginHelper();
$access_token = $helper->getAccessToken();
} catch (Facebook\Exceptions\FacebookResponseException $e) {
// When Graph returns an error.
Logger::getLogger('instantarticles-wp-plugin')->error('Graph returned an error: ' . $e->getMessage(), $e->getTraceAsString());
} catch (Facebook\Exceptions\FacebookSDKException $e) {
// When validation fails or other local issues.
Logger::getLogger('instantarticles-wp-plugin')->error('Facebook SDK returned an error: ' . $e->getMessage(), $e->getTraceAsString());
}
}
if (null !== $access_token) {
// Logged in.
return $access_token;
}
}
$_SESSION['facebook_access_token'] = (string) $accessToken;
// OAuth 2.0 client handler
$oAuth2Client = $fb->getOAuth2Client();
// Exchanges a short-lived access token for a long-lived one
$longLivedAccessToken = $oAuth2Client->getLongLivedAccessToken($_SESSION['facebook_access_token']);
$_SESSION['facebook_access_token'] = (string) $longLivedAccessToken;
$fb->setDefaultAccessToken($_SESSION['facebook_access_token']);
}
// validating the access token
try {
$request = $fb->get('/me');
} catch (Facebook\Exceptions\FacebookResponseException $e) {
// When Graph returns an error
if ($e->getCode() == 190) {
unset($_SESSION['facebook_access_token']);
$helper = $fb->getRedirectLoginHelper();
$loginUrl = $helper->getLoginUrl('https://apps.facebook.com/APP_NAMESPACE/', $permissions);
echo "<script>window.top.location.href='" . $loginUrl . "'</script>";
exit;
}
} catch (Facebook\Exceptions\FacebookSDKException $e) {
// When validation fails or other local issues
echo 'Facebook SDK returned an error: ' . $e->getMessage();
exit;
}
// getting basic info about user
try {
$profile_request = $fb->get('/me?fields=name,first_name,last_name,email');
$profile = $profile_request->getGraphNode()->asArray();
} catch (Facebook\Exceptions\FacebookResponseException $e) {
// When Graph returns an error
