Twitter oAuth无效的请求令牌

Question

I'm using the TwitterOAuth PHP library to connect my web page to Twitter, to retrieve authenticated user's data, but it's not working at all, I've been trying since yesterday and I've still not figured out how to do it.

This is my code:

    $twitter = new TwitterOAuth(CONSUMER_KEY, CONSUMER_SECRET);
    $credentials = $twitter->oauth('oauth/request_token', array('oauth_callback' => OAUTH_CALLBACK));
    $url = $twitter->url("oauth/authorize", array("oauth_token" => $credentials['oauth_token']));
    $_SESSION["oauth_token"] = $credentials["oauth_token"];
    $_SESSION["oauth_token_secret"] = $credentials["oauth_token_secret"];
    ?>
    <input type="button" name="contactTwitter" id="contactTwitter" onClick='window.location="<?php echo $url; ?>"' value="Connect to Twitter!"/>
    <?php
    if(isset($_GET['oauth_verifier'])) :
        $at=$twitter->oauth("oauth/access_token", array("oauth_verifier" => $_REQUEST['oauth_verifier']));
        var_dump($at);
    endif;

And it's not working at all. I've found lots of results to solve TwitterOAuth issues, but no one has helped me. I've understood Twitter API's functioning like sending request_token , receiving token_verifiers and obtaining access_tokens but it's not working here.
Thanks for help.

Answer 1

Problem solved.
I used another PHP file to get the TwitterOAuth callback result, which sends the access_token to my previous page which wasn't working.
In case that someone will need this, I'm posting the callback.php code:

require_once('config.php');
session_start();
use Abraham\TwitterOAuth\TwitterOAuth;
$request_token = array();
$request_token['oauth_token'] = $_SESSION['oauth_token'];
$request_token['oauth_token_secret'] = $_SESSION['oauth_token_secret'];

$connection = new TwitterOAuth(TW_CONSUMER_KEY, TW_CONSUMER_SECRET, $request_token['oauth_token'], $request_token['oauth_token_secret']);
$access_token = $connection->oauth("oauth/access_token", array("oauth_verifier" => $_REQUEST['oauth_verifier']));

if (200 == $connection->lastHttpCode()) {
    $_SESSION['access_token'] = $access_token;
    unset($_SESSION['oauth_token']);
    unset($_SESSION['oauth_token_secret']);
    $_SESSION['status'] = 'verified';
} else {
    session_destroy();
}

header('Location:./reg.php?st=3');

Than, in the registration page i just re-use the stored $_SESSION['access_token'] which I've found before.