Unable to load the requested class: Facebook using facebook php sdk codeigniter -

i want login facebook using facebook sdk php in codeigniter.

i have use facebook libary in applications/libraries/facebook.php

and full sdk path in applications/vendor

config of facebook app_id , app_secret in config folder config/facebook.php

in autoload.php load facebook library

$autoload['libraries'] = array('facebook','database','form_validation','session'); 

but got error unable load requested class: facebook

maybe didn't changed class name inside facebook library file, should facebook

1. check facebook file exist on libraries folder.
2. class name , file name of library must same. check it, capital , small letters.

check class name inside facebook php on library file.