Controlling Cacheability of Plugins' Output
Since Smarty-2.6.0 plugins the cacheability of plugins can be
declared when registering them. The third parameter to register_block(), register_compiler_function()
and register_function() is
called $cacheable and defaults to true which
is also the behaviour of plugins in Smarty versions before 2.6.0
When registering a plugin with $cacheable=false the plugin is
called everytime the page is displayed, even if the page comes
from the cache. The plugin function behaves a little like an
insert function.
In contrast to insert
the attributes to the plugins are not cached by default. They can be
declared to be cached with the fourth parameter
$cache_attrs. $cache_attrs
is an array of attribute-names that should be cached, so the
plugin-function get value as it was the time the page was written
to cache everytime it is fetched from the cache.
Example 14-10. Preventing a plugin's output from being cached
<?php
require('Smarty.class.php');
$smarty = new Smarty;
$smarty->caching = true;
function remaining_seconds($params, &$smarty) {
$remain = $params['endtime'] - time();
if ($remain >=0)
return $remain . " second(s)";
else
return "done";
}
$smarty->register_function('remaining', 'remaining_seconds', false, array('endtime'));
if (!$smarty->is_cached('index.tpl')) {
// fetch $obj from db and assign...
$smarty->assign_by_ref('obj', $obj);
}
$smarty->display('index.tpl');
?>
|
where index.tpl is:
Time Remaining: {remaining endtime=$obj->endtime} |
The number of seconds till the endtime of $obj is reached changes on
each display of the page, even if the page is cached. Since the
endtime attribute is cached the object only has to be pulled from the
database when page is written to the cache but not on subsequent requests
of the page.
|
Example 14-11. Preventing a whole passage of a template from being cached
index.php:
<?php
require('Smarty.class.php');
$smarty = new Smarty;
$smarty->caching = true;
function smarty_block_dynamic($param, $content, &$smarty) {
return $content;
}
$smarty->register_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.
