Chapter 5. Variable Modifiers [变量调节器]

Variable modifiers can be applied to variables, custom functions or strings. To apply a modifier, specify the value followed by the | (pipe) and the modifier name. A modifier may accept additional parameters that affect its behavior. These parameters follow the modifer name and are separated by : (colon).
变量调节器用于变量，自定义函数和字符串。 请使用‘|’符号和调节器名称应用调节器。 变量调节器由赋予的参数值决定其行为。 参数由‘：’符号分开。

{* Uppercase the title *}

<h2>{$title|upper}</h2>

{* Truncate the topic to 40 characters use ... at the end *}
Topic: {$topic|truncate:40:"..."}

{* format a literal string *}
{"now"|date_format:"%Y/%m/%d"}

{* apply modifier to a custom function *}
{mailto|upper address="me@domain.dom"}

If you apply a modifier to an array variable instead of a single value variable, the modifier will be applied to every value in that array. If you really want the modifier to work on an entire array as a value, you must prepend the modifier name with an @ symbol like so: {$articleTitle|@count} (this will print out the number of elements in the $articleTitle array.)
如果你给数组变量应用单值变量的调节，结果是数组的每个值都被调节。 如果你只想要调节器用一个值调节整个数组，你必须在调节器名字前加上@符号。 例如： {$articleTitle|@count}（这将会在 $articleTitle 数组里输出元素的数目）

Modifiers can be autoloaded from your $plugins_dir (also see: Naming Conventions) or can be registered explicitely (see: register_modifier). Additionally all php-functions can be used as modifiers implicitely. (The @count-example above actually uses php's count-function and not a smarty-modifier). Using php-functions as modifiers has two little pitfalls: First: Sometimes the order of the function-parameters is not the desirable one ({"%2.f"|sprintf:$float} actually works, but asks for the more intuitive {For example: $float|string_format:"%2.f"} that is provided by the Smarty distribution). Second: with $security turned on all php-functions that are to be used as modifiers have to be declared trusted in the $security_settings['MODIFIER_FUNCS']-array.

index.php:

$smarty = new Smarty;
$smarty->assign('articleTitle', 'Police begin campaign to rundown jaywalkers.');
$smarty->display('index.tpl');

index.tpl:

{$articleTitle}
{$articleTitle|capitalize}

OUTPUT:

Police begin campaign to rundown jaywalkers.
Police Begin Campaign To Rundown Jaywalkers.