/**
* Obtains the SSO URL containing the AuthRequest
* message deflated.
*
* @param OneLogin_Saml2_Settings $settings Settings
*/
public function getRedirectUrl($returnTo = null)
{
$settings = $this->auth->getSettings();
$authnRequest = new OneLogin_Saml2_AuthnRequest($settings);
$parameters = array('SAMLRequest' => $authnRequest->getRequest());
if (!empty($returnTo)) {
$parameters['RelayState'] = $returnTo;
} else {
$parameters['RelayState'] = OneLogin_Saml2_Utils::getSelfURLNoQuery();
}
$url = OneLogin_Saml2_Utils::redirect($this->auth->getSSOurl(), $parameters, true);
return $url;
}