include_php

include_php tags are used to include a php script in your template. If security is enabled, then the php script must be located in the $trusted_dir path. The include_php tag must have the attribute "file", which contains the path to the included php file, either relative to $trusted_dir, or an absolute path.

inluce_php 函数用于在模板中包含 php 脚本. 如果设置了安全模式，被包含的脚本必须位于 $trusted_dir 路径下. include_php 函数必须设置 file 属性，该属性指明被包含 php 文件的路径，可以是 $trusted_dir 的相对路径，也可以是绝对路径.

include_php is a nice way to handle componentized templates, and keep PHP code separate from the template files. Lets say you have a template that shows your site navigation, which is pulled dynamically from a database. You can keep your PHP logic that grabs database content in a separate directory, and include it at the top of the template. Now you can include this template anywhere without worrying if the database information was assigned by the application before hand.

include_php 是解决模板部件化的好方法，它使得 php 代码从模板文件中被分离出来. 举个例子：假设有一个从数据库中动态取出数据用于显示站点导航的模板，你可以将得数据内容的 php 逻辑部分分离出来保存在一个单独的文件夹下，并在模板开始的位置包含该 php 脚本. 那么就可以在任何地方包含此模板而不用担心之前数据库信息是否已被程序取出.

By default, php files are only included once even if called multiple times in the template. You can specify that it should be included every time with the once attribute. Setting once to false will include the php script each time it is included in the template.

即使是在模板中多次地调用 php 文件，默认情况下它们只被包含一次. 你可以设置 once 属性从而指明每次调用都重新包含该文件. 如果将 once 属性设置为 false，每次调用该文件都将被重新包含.

You can optionally pass the assign attribute, which will specify a template variable name that the output of include_php will be assigned to instead of displayed.

如果设置了 assign 属性，该属性对应的变量名用于保存待包含 php 的输出，这样待包含 php 文件的输出就不会直接显示了。

The smarty object is available as $this within the PHP script that you include.

在待包含 php 文件中可以通过 $this 访问 smarty 对象.

load_nav.php
-------------

<?php

	// load in variables from a mysql db and assign them to the template
	// 从mysql数据库中取得数据，将数据赋给模板变量
	require_once("MySQL.class.php");
	$sql = new MySQL;
	$sql->query("select * from site_nav_sections order by name",SQL_ALL);
	$this->assign('sections',$sql->record);

?>


index.tpl
---------

{* absolute path, or relative to $trusted_dir *}
{* 绝对路径或 $trusted_dir 的相对路径 *}
{include_php file="/path/to/load_nav.php"}

{foreach item="curr_section" from=$sections}
	<a href="{$curr_section.url}">{$curr_section.name}</a><br>
{/foreach}