mirror of
https://github.com/silverstripe/silverstripe-framework
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e632ee3e52
- create a new documentation section explaining the "cached" block - clean up the Performance documentation section, moving explanations about "cached" block away, adding new warnings and recommendations
46 lines
961 B
Markdown
46 lines
961 B
Markdown
---
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title: Caching
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summary: How template variables are cached.
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icon: rocket
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---
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# Caching
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## Object caching
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All functions that provide data to templates must have no side effects, as the value is cached after first access. For
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example, this controller method will not behave as you might imagine.
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```php
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private $counter = 0;
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public function Counter()
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{
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$this->counter += 1;
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return $this->counter;
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}
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```
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```ss
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$Counter, $Counter, $Counter
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// returns 1, 1, 1
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```
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When we render `$Counter` to the template we would expect the value to increase and output `1, 2, 3`. However, as
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`$Counter` is cached at the first access, the value of `1` is saved.
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## Partial caching
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Partial caching is a feature that allows caching of a portion of a page as a single string value. For more details read [its own documentation](partial_template_caching).
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Example:
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```ss
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<% cached $CacheKey if $CacheCondition %>
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$CacheableContent
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<% end_cached %>
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```
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