includefile.modxsnippet.php

<?php
# Snippet to include files from filesystem
# [[includeFile? &file=`assets/templates/mytemplate/file.html`]]

if ( !isset($file) || $file== "" ) return "No file specified."; //check if there's a file given.

//Start the buffer
ob_start();

//include
include $file;

//get contents from the buffer
$ob_contents = ob_get_contents();

//and kill/delete the buffer
ob_end_clean();

//return it to MODx
return $ob_contents;
?>