smarty/docs/programmers/caching/caching-cacheable.md

Controlling Cacheability of Output

If caching is enabled normally the whole final output of the page gets cached. However Smarty3 offers several options how to exclude sections of your output from caching.

Note

Be sure any variables used within a non-cached section are also assigned from PHP when the page is loaded from the cache.

Cacheability of Template Section

A larger section of your template can easily excluded from caching by using the {nocache} and {/nocache} tags.

Today's date is
{nocache}
{$smarty.now|date_format}
{/nocache}

The above code will output the current date on a cached page.

Cacheability of Tags

Caching for an individual tag can be disabled by adding the "nocache" option flag to the tag.

Today's date is
{$smarty.now|date_format nocache}

Cacheability of Variables

You can assign() variables as not cachable. Any tag which uses such variable will be automatically executed in nocache mode.

Note

If a tag is executed in nocache mode you must make sure that all other variables used by that tag are also assigned from PHP when the page is loaded from the cache.

Note

The nocache status of an assigned variable will effect the compiled template code. If you change the status you must manually delete existing compiled and cached template files to force a recompile.

// assign $foo as nocahe variable
$smarty->assign('foo',time(),true);


Dynamic time value is {$foo}

Cacheability of Plugins

The cacheability of plugins can be declared when registering them. The third parameter to registerPlugin() is called $cacheable and defaults to TRUE.

When registering a plugin with $cacheable=false the plugin is called everytime the page is displayed, even if the page comes from the cache.

Note

The $cacheable status will affect the compiled template code. If you change the status you must manually delete existing compiled and cached template files to force a recompile.

Example index.php:

<?php
$smarty->setCaching(Smarty::CACHING_LIFETIME_CURRENT);

function smarty_block_dynamic($param, $content, $smarty) {
    return $content;
}
$smarty->registerPlugin('block','dynamic', 'smarty_block_dynamic', false);

$smarty->display('index.tpl');
?>

where index.tpl is:

Page created: {'0'|date_format:'%D %H:%M:%S'}

{dynamic}

Now is: {'0'|date_format:'%D %H:%M:%S'}

... do other stuff ...

{/dynamic}

When reloading the page you will notice that both dates differ. One is "dynamic" one is "static". You can do everything between {dynamic}...{/dynamic} and be sure it will not be cached like the rest of the page.

Note

The above example shall just demonstrate how a dynamic block plugins works. See Cacheability of Template Section on how to disable caching of a template section by the built-in {nocache} and {/nocache} tags.