88 lines
2.7 KiB
Markdown
88 lines
2.7 KiB
Markdown
|
Multiple Caches Per Page {#caching.multiple.caches}
|
||
|
|
========================
|
||
|
|
|
||
|
|
You can have multiple cache files for a single call to
|
||
|
|
[`display()`](#api.display) or [`fetch()`](#api.fetch). Let\'s say that
|
||
|
|
a call to `display('index.tpl')` may have several different output
|
||
|
|
contents depending on some condition, and you want separate caches for
|
||
|
|
each one. You can do this by passing a `$cache_id` as the second
|
||
|
|
parameter to the function call.
|
||
|
|
|
||
|
|
|
||
|
|
<?php
|
||
|
|
require('Smarty.class.php');
|
||
|
|
$smarty = new Smarty;
|
||
|
|
|
||
|
|
$smarty->setCaching(Smarty::CACHING_LIFETIME_CURRENT);
|
||
|
|
|
||
|
|
$my_cache_id = $_GET['article_id'];
|
||
|
|
|
||
|
|
$smarty->display('index.tpl', $my_cache_id);
|
||
|
|
?>
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
Above, we are passing the variable `$my_cache_id` to
|
||
|
|
[`display()`](#api.display) as the `$cache_id`. For each unique value of
|
||
|
|
`$my_cache_id`, a separate cache will be generated for `index.tpl`. In
|
||
|
|
this example, `article_id` was passed in the URL and is used as the
|
||
|
|
`$cache_id`.
|
||
|
|
|
||
|
|
> **Note**
|
||
|
|
>
|
||
|
|
> Be very cautious when passing values from a client (web browser) into
|
||
|
|
> Smarty or any PHP application. Although the above example of using the
|
||
|
|
> article\_id from the URL looks handy, it could have bad consequences.
|
||
|
|
> The `$cache_id` is used to create a directory on the file system, so
|
||
|
|
> if the user decided to pass an extremely large value for article\_id,
|
||
|
|
> or write a script that sends random article\_id\'s at a rapid pace,
|
||
|
|
> this could possibly cause problems at the server level. Be sure to
|
||
|
|
> sanitize any data passed in before using it. In this instance, maybe
|
||
|
|
> you know the article\_id has a length of ten characters and is made up
|
||
|
|
> of alpha-numerics only, and must be a valid article\_id in the
|
||
|
|
> database. Check for this!
|
||
|
|
|
||
|
|
Be sure to pass the same `$cache_id` as the second parameter to
|
||
|
|
[`isCached()`](#api.is.cached) and [`clearCache()`](#api.clear.cache).
|
||
|
|
|
||
|
|
|
||
|
|
<?php
|
||
|
|
require('Smarty.class.php');
|
||
|
|
$smarty = new Smarty;
|
||
|
|
|
||
|
|
$smarty->setCaching(Smarty::CACHING_LIFETIME_CURRENT);
|
||
|
|
|
||
|
|
$my_cache_id = $_GET['article_id'];
|
||
|
|
|
||
|
|
if(!$smarty->isCached('index.tpl',$my_cache_id)) {
|
||
|
|
// No cache available, do variable assignments here.
|
||
|
|
$contents = get_database_contents();
|
||
|
|
$smarty->assign($contents);
|
||
|
|
}
|
||
|
|
|
||
|
|
$smarty->display('index.tpl',$my_cache_id);
|
||
|
|
?>
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
You can clear all caches for a particular `$cache_id` by passing NULL as
|
||
|
|
the first parameter to [`clearCache()`](#api.clear.cache).
|
||
|
|
|
||
|
|
|
||
|
|
<?php
|
||
|
|
require('Smarty.class.php');
|
||
|
|
$smarty = new Smarty;
|
||
|
|
|
||
|
|
$smarty->setCaching(Smarty::CACHING_LIFETIME_CURRENT);
|
||
|
|
|
||
|
|
// clear all caches with "sports" as the $cache_id
|
||
|
|
$smarty->clearCache(null,'sports');
|
||
|
|
|
||
|
|
$smarty->display('index.tpl','sports');
|
||
|
|
?>
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
In this manner, you can "group" your caches together by giving them the
|
||
|
|
same `$cache_id`.
|