Smarty的模板中不允许PHP的代码？

/******************************************************************************
 *                  Smarty的模板中不允许PHP的代码？
 * 说明：
 *     在将PHP的代码转换为Smarty的模板的过程中，遇到Smarty无法转换PHP代码的问题，
 * 原因是这个功能被禁止了，因为既然使用Smarty模板，那么PHP代码做的事情尽量放在
 * Controller那里，这样可读性会更高。
 *
 *                                         2017-3-13 深圳 南山平山村 曾剑锋
 *****************************************************************************/

一、参考文档：
    . Using PHP code in Smarty tpl FIle
        http://stackoverflow.com/questions/7446851/using-php-code-in-smarty-tpl-file
    . Using PHP inside Smarty template files [duplicate]
        http://stackoverflow.com/questions/14877736/using-php-inside-smarty-template-files
    . How to add PHP code to .tpl file [duplicate]
        http://stackoverflow.com/questions/9601547/how-to-add-php-code-to-tpl-file
    . Using PHP code in Smarty tpl FIle
        http://stackoverflow.com/questions/7446851/using-php-code-in-smarty-tpl-file
    . Difference between Smarty and SmartyBC classes
        http://stackoverflow.com/questions/35863410/difference-between-smarty-and-smartybc-classes

二、原因：
    . SmartyBC is a Backwards Compatibility Wrapper. it allows {php} and {include_php} inside templates. Both tags were dropped with the Smarty 3.1 release.
    . You shouldn't add PHP code to the template. It will make whole idea of templates spoiled. You have to add PHP code to controller, not template.