Now I'm Using Facebook SDK v5.0 after pressing "login With Facebook" its automatically redirect to "callback.php" and long lived access token should be issued. but
This error appears every time.
Facebook SDK returned an error: Cross-site request forgery validation failed. Required param "state" missing.
if you have any solutions to solve this error please tell me.
here is my code:callback.php
<html>
<meta charset="UTF-8" content="text/html">
<?php
session_start();
require_once __DIR__ . '/facebook-php-sdk-v4-5.0-dev/src/Facebook/autoload.php';
$fb = new Facebook\Facebook([
'app_id' => '3xxxxxxxxxxxxxxxxxx7',
'app_secret' => '0xxxxxxxxxxxxxxxxxxxx7',
'default_graph_version' => 'v2.4',
]);
$helper = $fb->getRedirectLoginHelper();
try {
$accessToken = $helper->getAccessToken();
} catch(Facebook\Exceptions\FacebookResponseException $e) {
// When Graph returns an error
echo 'Graph returned an error: ' . $e->getMessage();
exit;
} catch(Facebook\Exceptions\FacebookSDKException $e) {
// When validation fails or other local issues
echo 'Facebook SDK returned an error: ' . $e->getMessage();
exit;
}
if (! isset($accessToken)) {
if ($helper->getError()) {
header('HTTP/1.0 401 Unauthorized');
echo "Error: " . $helper->getError() . "\n";
echo "Error Code: " . $helper->getErrorCode() . "\n";
echo "Error Reason: " . $helper->getErrorReason() . "\n";
echo "Error Description: " . $helper->getErrorDescription() . "\n";
} else {
header('HTTP/1.0 400 Bad Request');
echo 'Bad request';
}
exit;
}
// Logged in
echo '<h3>Access Token</h3>';
var_dump($accessToken->getValue());
// The OAuth 2.0 client handler helps us manage access tokens
$oAuth2Client = $fb->getOAuth2Client();
// Get the access token metadata from /debug_token
$tokenMetadata = $oAuth2Client->debugToken($accessToken);
echo '<h3>Metadata</h3>';
var_dump($tokenMetadata);
// Validation (these will throw FacebookSDKException's when they fail)
$tokenMetadata->validateAppId($config['app_id']);
// If you know the user ID this access token belongs to, you can validate it here
//$tokenMetadata->validateUserId('123');
$tokenMetadata->validateExpiration();
if (! $accessToken->isLongLived()) {
// Exchanges a short-lived access token for a long-lived one
try {
$accessToken = $oAuth2Client->getLongLivedAccessToken($accessToken);
} catch (Facebook\Exceptions\FacebookSDKException $e) {
echo "<p>Error getting long-lived access token: " . $helper->getMessage() . "</p>\n\n";
exit;
}
echo '<h3>Long-lived</h3>';
var_dump($accessToken->getValue());
}
$_SESSION['fb_access_token'] = (string) $accessToken;
// User is logged in with a long-lived access token.
// You can redirect them to a members-only page.
//header('Location: https://example.com/members.php');
?>
</html>
just in case, I'm posting this too. :login.php
<html>
<meta charset="UTF-8" content="text/html">
<?php
session_start();
require_once __DIR__ . '/facebook-php-sdk-v4-5.0-dev/src/Facebook/autoload.php';
$fb = new Facebook\Facebook([
'app_id' => '3xxxxxxxxxxxxxxxxx7',
'app_secret' => '0xxxxxxxxxxxxxxxxxxx7',
'default_graph_version' => 'v2.4',
]);
$helper = $fb->getRedirectLoginHelper();
$permissions = ['email']; // Optional permissions
$loginUrl = $helper->getLoginUrl('http://127.0.0.1:8887/fb/fb-callback.php', $permissions);
echo '<a href="' . $loginUrl . '">Log in with Facebook!</a>';
?>
</html>