Joomla教程中的简单PHP相对路径

考虑到本文为Joomla开发MVC组件，以下是包含通用模板的代码

$pathToGeneralView = strchr(dirname(__FILE__), dirname($_SERVER['SCRIPT_NAME']));
$pathToGeneralView = str_replace(dirname($_SERVER['SCRIPT_NAME']),'.',$pathToGeneralView );
$pathToGeneralView = $pathToGeneralView . "/../../general/";  <-- returning path from current position. 
...
<?php require_once $pathToGeneralView . 'navigate.header.php'; ?>
<P>Do something    
<?php require_once $pathToGeneralView . 'navigate.footer.php'; ?>

通过文件系统层次结构，

./com_compname/views/general/navigate.header.php  <-- sniplet code for the header
./com_compname/views/general/navigate.footer.php  <-- sniplet code for the footer
./com_compname/views/mngtable1/view.html.php
./com_compname/views/mngtable1/tmpl/default.php *
./com_compname/views/mngtable2/view.html.php
./com_compname/views/mngtable2/tmpl/default.php *

既然通用模板组件就在../../general文件夹下，为什么作者要麻烦使用strchr、str_replace来处理文件夹路径？../../general/navigate.header.php或../../general/navigate.footer.php还不够吗？

谢谢。