Custom Login/Logout handling for using WordPress as a CMS

functions.php

/*Login Error Handle*/
add_action( 'wp_login_failed', 'aa_login_failed' ); // hook failed login

function aa_login_failed( $user ) {
  	// check what page the login attempt is coming from
  	$referrer = $_SERVER['HTTP_REFERER'];

  	// check that were not on the default login page
	if ( !empty($referrer) && !strstr($referrer,'wp-login') && !strstr($referrer,'wp-admin') && $user!=null ) {
		// make sure we don't already have a failed login attempt
		if ( !strstr($referrer, '?login=failed' )) {
			// Redirect to the login page and append a querystring of login failed
	    	wp_redirect( $referrer . '?login=failed');
	    } else {
	      	wp_redirect( $referrer );
	    }

	    exit;
	}
}

/*Login Empty Fields Error handling*/
add_action( 'authenticate', 'pu_blank_login');

function pu_blank_login( $user ){
  	// check what page the login attempt is coming from
  	$referrer = $_SERVER['HTTP_REFERER'];

  	$error = false;

  	if($_POST['log'] == '' || $_POST['pwd'] == '')
  	{
  		$error = true;
  	}

  	// check that were not on the default login page
  	if ( !empty($referrer) && !strstr($referrer,'wp-login') && !strstr($referrer,'wp-admin') && $error ) {

  		// make sure we don't already have a failed login attempt
    	if ( !strstr($referrer, '?login=failed') ) {
    		// Redirect to the login page and append a querystring of login failed
        	wp_redirect( $referrer . '?login=failed' );
      	} else {
        	wp_redirect( $referrer );
      	}

    exit;

  	}
}

/*Logout Redirect*/
add_filter( 'login_redirect', 'my_login_redirect', 10, 3 );

function go_home(){
  wp_redirect( home_url('/login/') );
  exit();
}
add_action('wp_logout','go_home');