<?php

$smarty = new Smarty();
$smarty->default_template_handler_func = 'my_default_template_handler_func';

/**
 * Default Template Handler
 *
 * called when Smarty's file: resource is unable to load a requested file
 * 
 * @param string   $type     resource type (e.g. "file", "string", "eval", "resource")
 * @param string   $name     resource name (e.g. "foo/bar.tpl")
 * @param string  &$content  template's content
 * @param integer &$modified template's modification time
 * @param Smarty   $smarty   Smarty instance
 * @return string|boolean   path to file or boolean true if $content and $modified 
 *                          have been filled, boolean false if no default template 
 *                          could be loaded
 */
function my_default_template_handler_func($type, $name, &$content, &$modified, Smarty $smarty) {
    if (false) {
        // return corrected filepath
        return "/tmp/some/foobar.tpl";
    } elseif (false) {
        // return a template directly
        $content = "the template source";
        $modified = time();
        return true;
    } else {
        // tell smarty that we failed
        return false;
    }
}

?>