Understanding Smarty Template Variables: Assignment, Reserved, and Custom Variables

In Smarty templates, a template variable is a variable assigned to the template and accessed according to Smarty's parsing rules.

Smarty categorises template variables into three groups:

PHP‑assigned variables, created with the assign method.

Reserved Smarty variables, which include super‑global predefined variables and built‑in Smarty variables.

Custom variables, defined directly inside the template.

1. PHP‑assigned variables – PHP can assign any data type to the template, typically scalar, array, or object data.

Scalar data: output directly.

Array data: accessed via index notation (e.g., {$arr1[0]} ) or dot notation (e.g., {$arr1.0} ).

Object data: accessed using the object operator (e.g., {$object1->name} ).

<code>&lt;?php
require 'smarty/Smarty.class.php';
$smarty = new Smarty();
// $smarty->left_delimiter = "<{";
// $smarty->right_delimiter = "}>";
$smarty->template_dir = 'templates/'; // actual template directory

// scalar
$smarty->assign('hello', "hello world");
// array
$smarty->assign('arr1', array(1412, 14, 23, 456));
$smarty->assign('arr2', array('name'=>'张三', 'sex'=>'男'));
// object
class Person {
    public $name = '陈平安';
    public $perr = 'saber';
}
$smarty->assign('object1', new Person());
$smarty->display('model.html');
?&gt;
</code>

<code>&lt;!DOCTYPE html&gt;
&lt;html&gt;
&lt;head&gt;&lt;title&gt;&lt;/title&gt;&lt;/head&gt;
&lt;body&gt;
    {$hello} 这是templates下面的模板 &lt;br&gt;
    这是索引数组：{$arr1[0]}---{$arr1[1]}---{$arr1[2]} &lt;br&gt;
    这是索引数组：{$arr1.0}---{$arr1.1}---{$arr1.2} &lt;br&gt;
    这是关联数组：{$arr2.name}---{$arr2.sex} &lt;br&gt;
    这是对象：{$object1->name}---{$object1->perr} &lt;br&gt;
&lt;/body&gt;
&lt;/html&gt;
</code>

2. Reserved Smarty variables – These are system or internal variables that start with $smarty and are frequently used, such as:

GET data: {$smarty.get.name}

POST data: {$smarty.post.name}

Session data: {$smarty.session.username}

Cookie data: {$smarty.cookies.username}

REQUEST data: {$smarty.request.name}

Server data: {$smarty.server.SERVER_NAME}

Timestamp: {$smarty.now}

Current template directory: {$smarty.current_dir}

Template name: {$smarty.template}

Config values: {$smarty.config.key}

<code>&lt;html&gt;
    &lt;header&gt;&lt;/header&gt;
    &lt;body&gt;
        GET data: {$smarty.get.name}<br/>
        POST data: {$smarty.post.name}<br/>
        Session data: {$smarty.session.username}<br/>
        Cookie data: {$smarty.cookies.username}<br/>
        REQUEST data: {$smarty.request.name}<br/>
        Server data: {$smarty.server.SERVER_NAME}<br/>
        Timestamp: {$smarty.now}<br/>
        Template path: {$smarty.current_dir}<br/>
        Template name: {$smarty.template}
    &lt;/body&gt;
&lt;/html&gt;
</code>

3. Custom variables – Smarty allows defining variables directly in the template using the {assign} tag, for example:

<code>&lt;html&gt;
    &lt;header&gt;&lt;/header&gt;
    &lt;body&gt;
        {assign var='name' value='Sun'}
        {$name}
    &lt;/body&gt;
&lt;/html&gt;
</code>

The article concludes with a link to the original source for further reading.