$autoload_filters
自动加载过滤器变量

If there are some filters that you wish to load on every template invocation, you can specify them using this variable and Smarty will automatically load them for you. The variable is an associative array where keys are filter types and values are arrays of the filter names. For example:
如果你希望在每次模板调用过程中加载过滤器,你可以指定他们使用此变量,Smarty将自动为你加载它们.该变量是一个联合数组,在数组中键是过滤器类型,值是过滤器名字所组成的数组.例如:

$smarty->autoload_filters = array('pre' => array('trim', 'stamp'),
                                  'output' => array('convert'));