mirror of
https://github.com/silverstripe/silverstripe-framework
synced 2024-07-22 03:13:58 +02:00
47 lines
1.0 KiB
Markdown
47 lines
1.0 KiB
Markdown
title: Caching
|
|
summary: Reduce rendering time with cached templates and understand the limitations of the ViewableData object caching.
|
|
|
|
# Caching
|
|
|
|
## Object caching
|
|
|
|
All functions that provide data to templates must have no side effects, as the value is cached after first access. For
|
|
example, this controller method will not behave as you might imagine.
|
|
|
|
```php
|
|
private $counter = 0;
|
|
|
|
public function Counter()
|
|
{
|
|
$this->counter += 1;
|
|
|
|
return $this->counter;
|
|
}
|
|
```
|
|
|
|
|
|
```ss
|
|
|
|
$Counter, $Counter, $Counter
|
|
|
|
// returns 1, 1, 1
|
|
```
|
|
|
|
When we render `$Counter` to the template we would expect the value to increase and output `1, 2, 3`. However, as
|
|
`$Counter` is cached at the first access, the value of `1` is saved.
|
|
|
|
|
|
## Partial caching
|
|
|
|
Partial caching is a feature that allows the caching of just a portion of a page. Instead of fetching the required data
|
|
from the database to display, the contents of the area are fetched from a [cache backend](../performance/caching).
|
|
|
|
```ss
|
|
|
|
<% cached 'MyCachedContent', LastEdited %>
|
|
$Title
|
|
<% end_cached %>
|
|
```
|
|
|
|
|