Core class for OAuth 2.0 implementation.

EXAMPLE:

class LinkedInOAuth2 extends OAuth2 {
    public function __construct($access_token=''){
        $this->access_token_url = "https://www.linkedin.com/uas/oauth2/accessToken";
        $this->authorize_url = "https://www.linkedin.com/uas/oauth2/authorization";
        parent::__construct($access_token);
        $this->access_token_name='oauth2_access_token';
    }
    public function getAuthorizeUrl($client_id,$redirect_url,$scope=''){
        $additional_args = array();
        if($scope!=''){
            if(is_array($scope)){
                $additional_args['scope']=implode(' ',$scope);
                $additional_args['scope'] = urlencode($additional_args['scope']);
            }else{
                $additional_args['scope'] = urlencode($scope);
            }
        }
        $additional_args['state'] = md5(time());
        return parent::getAuthorizeUrl($client_id,$redirect_url,$additional_args);
    }

    public function getAccessToken($client_id="", $secret="", $redirect_url="", $code = ""){
        $result = parent::getAccessToken($client_id, $secret, $redirect_url, $code);
        $result = json_decode($result,true); 
        if(isset($result['error'])){
            $this->error = $result['error'].' '.$result['error_description'];
            return false;
        }else{
            $this->access_token = $result['access_token'];
            return $result['access_token'];
    }
    public function getConnections(){
        $params=array();
        $params['url'] = "https://api.linkedin.com/v1/people/~/connections";
        $params['method']='get';
        $params['args']['format']='json';
        $result =  $this->makeRequest($params);
        return json_decode($result,true); 
    }
}

Main method to make the call is makeRequest($params); .

$params is array:

$params['url'] = "...";//url to make the call
$params['method'] = "post";//method, get, post, put, delete
$params['headers'] = array('Content-Type'=>'application/json', 'x-li-format'=>'json'); // list of headers $header_name=>$header_value
$params['args'] = array('count'=>200);//any arguments to pass in request
or
$params['args'] = 'any text xml or json for example';//to pass plain text in post request for example