Checking for PMPro membership when accessing non-WP pages.

my_pmpro_getfile_before_readfile.php

/**
 * Checking for membership when accessing non-WP pages.
 * This code will work with the htaccess rewrite rules shared here:
 * https://www.paidmembershipspro.com/locking-non-wordpress-files-folders-paid-memberships-pro/
 */
function my_pmpro_getfile_before_readfile( $filename, $file_mimetype ) {	
	if(is_dir($filename)) {
		$filename .= "index.html";
		$mimetype = new pmpro_mimetype();
		$file_mimetype = $mimetype->getType($filename);
	}
	
	if(!pmpro_hasMembershipLevel()) {		
		wp_redirect(wp_login_url());
		exit;
	}
	
	//if file is not found, die
	if(!file_exists($filename))
	{
		status_header( 404 );
			nocache_headers();        
			die("File not found.");
	}
	
	//if blacklistsed file type, redirect to it instead
	$basename = basename($filename);
	$parts = explode('.', $basename);
	$ext = strtolower($parts[count($parts)-1]);
	
	//build blacklist and allow for filtering
	$blacklist = array("inc", "php", "php3", "php4", "php5", "phps", "phtml");
	$blacklist = apply_filters("pmpro_getfile_extension_blacklist", $blacklist);
	
	//check
	if(in_array($ext, $blacklist))
	{		
		//add a noloop param to avoid infinite loops
		$uri = add_query_arg("noloop", 1, $uri);
		
		//guess scheme and add host back to uri
		if(is_ssl())
			$uri = "https://" . $_SERVER['HTTP_HOST'] . "/" . $uri;
		else
			$uri = "http://" . $_SERVER['HTTP_HOST'] . "/" . $uri;
				
		wp_redirect($uri);
		exit;
	}
		
	require_once(PMPRO_DIR . '/classes/class.mimetype.php');
	
	//okay show the file
	header("Content-type: " . $file_mimetype); 	
	readfile($filename);
	exit;
}
add_action('pmpro_getfile_before_readfile', 'my_pmpro_getfile_before_readfile', 10, 2);