$default_resource_type
默认源类型变量

This tells smarty what resource type to use implicitly. The default value is "file", meaning that $smarty->display("index.tpl"); and $smarty->display("file:index.tpl"); are identical in meaning. See the resource chapter for details.
该变量告诉smarty隐式地使用什么源类型.默认值为"file",也就是说,$smarty->display("index.tpl");和and $smarty->display("file:index.tpl");从意思上是一样的.祥见resource一章。