Here is a simple Twitter class -

<?php
class Twitter {
private $credentials;

function Twitter($username, $password) {
$this->credentials = sprintf("%s:%s", $username, $password);
}

function verifyCredentials($format = NULL) {
$api_call = sprintf("http://twitter.com/account/verify_credentials%s", ($format != NULL) ? sprintf(".%s", $format) : NULL);
return $this->APICall($api_call, true);
}

private function APICall($api_url, $require_credentials = false, $http_post = false) {
$curl_handle = curl_init();
curl_setopt($curl_handle, CURLOPT_URL, $api_url);

if ($require_credentials) {
curl_setopt($curl_handle, CURLOPT_USERPWD, $this->credentials);

}
if ($http_post) {
curl_setopt($curl_handle, CURLOPT_POST, true);
}
curl_setopt($curl_handle, CURLOPT_RETURNTRANSFER, TRUE);
$twitter_data = curl_exec($curl_handle);

curl_close($curl_handle);
return $twitter_data;
}
}
?>

Then here is the simple action to handle form –

public function executeTwitterLogin()
{
if ($this->getRequest()->getMethod() == sfRequest::POST)
{
$username = $this->getRequestParameter('username');
$password =  $this->getRequestParameter('password');

// Your business logic here...
}
}

Here is the action to handle error for TwitterLogin action –

public function handleTwitterLogin()
{
return sfView::SUCCESS;
}

Here is a simple template with the form asking for the Twitter login credentials -

<?php use_helper('Validation', 'Form') ?>

<?php echo form_tag('@twitter_login') ?>

<p>Please enter your Twitter account's login credentials below.</p>

<?php echo form_error('username') ?>
<label for="username">Twitter Username:</label>
<?php echo input_tag('username', $sf_params->get('username')) ?>

<?php echo form_error('password') ?>
<label for="password">Twitter Password:</label>
<?php echo input_password_tag('password') ?>

<?php echo submit_tag('Login') ?>
</form>

Here is the twitterLogin.yml validator file –

methods:
post: [username, password]

names:
username:
required:     true
required_msg: Your Twitter Username is required.
validators:   userValidator

password:
required:     true
required_msg: Your Twitter Password is required.

userValidator:
class:        twitterLoginValidator
param:
password:    password

And finally, here is the custom class which is extended from sfvalidator for authenticating Twitter login details.

<?php
class myTwitterLoginValidator extends sfValidator
{
public function initialize($context, $parameters = null)
{
// initialize parent
parent::initialize($context);

// set defaults
$this->setParameter('error', 'Your Twitter account credentials are incorrect.');
$this->getParameterHolder()->add($parameters);

return true;
}

public function execute(&amp;$value, &amp;$error)
{
$password_param = $this->getParameter('password');
$password = $this->getContext()->getRequest()->getParameter($password_param);

$username = $value;

// Verify Twitter Credentials
$twitter = new Twitter($username, $password);
$resp_xml = $twitter->verifyCredentials('xml');
$resp_xml = simplexml_load_string($resp_xml);

$resp_username = $resp_xml->screen_name;
$verified = strcasecmp($username, $resp_username); // returns 0 if they are equal

if ($verified === 0)
return true;

$error = $this->getParameter('error');
return false;
}
}
?>

I hope you’ll find this useful. Let me know in the comments section if you see any issue while using it.