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Diffstat (limited to 'guides/source/caching_with_rails.md')
| -rw-r--r-- | guides/source/caching_with_rails.md | 19 |
1 files changed, 14 insertions, 5 deletions
diff --git a/guides/source/caching_with_rails.md b/guides/source/caching_with_rails.md index abab3dd983..1e196b0e42 100644 --- a/guides/source/caching_with_rails.md +++ b/guides/source/caching_with_rails.md @@ -5,8 +5,8 @@ This guide will teach you what you need to know about avoiding that expensive ro After reading this guide, you will know: -* Page, action, and fragment caching. -* Sweepers. +* Page and action caching (moved to separate gems as of Rails 4). +* Fragment caching. * Alternative cache stores. * Conditional GET support. @@ -30,13 +30,13 @@ config.action_controller.perform_caching = true Page caching is a Rails mechanism which allows the request for a generated page to be fulfilled by the webserver (i.e. Apache or nginx), without ever having to go through the Rails stack at all. Obviously, this is super-fast. Unfortunately, it can't be applied to every situation (such as pages that need authentication) and since the webserver is literally just serving a file from the filesystem, cache expiration is an issue that needs to be dealt with. -INFO: Page Caching has been removed from Rails 4. See the [actionpack-page_caching gem](https://github.com/rails/actionpack-page_caching) +INFO: Page Caching has been removed from Rails 4. See the [actionpack-page_caching gem](https://github.com/rails/actionpack-page_caching). See [DHH's key-based cache expiration overview](http://37signals.com/svn/posts/3113-how-key-based-cache-expiration-works) for the newly-preferred method. ### Action Caching Page Caching cannot be used for actions that have before filters - for example, pages that require authentication. This is where Action Caching comes in. Action Caching works like Page Caching except the incoming web request hits the Rails stack so that before filters can be run on it before the cache is served. This allows authentication and other restrictions to be run while still serving the result of the output from a cached copy. -INFO: Action Caching has been removed from Rails 4. See the [actionpack-action_caching gem](https://github.com/rails/actionpack-action_caching) +INFO: Action Caching has been removed from Rails 4. See the [actionpack-action_caching gem](https://github.com/rails/actionpack-action_caching). See [DHH's key-based cache expiration overview](http://37signals.com/svn/posts/3113-how-key-based-cache-expiration-works) for the newly-preferred method. ### Fragment Caching @@ -104,6 +104,15 @@ This method generates a cache key that depends on all products and can be used i All available products: <% end %> ``` + +If you want to cache a fragment under certain condition you can use `cache_if` or `cache_unless` + +```erb +<% cache_if (condition, cache_key_for_products) do %> + All available products: +<% end %> +``` + You can also use an Active Record model as the cache key: ```erb @@ -236,7 +245,7 @@ config.cache_store = :ehcache_store When initializing the cache, you may use the `:ehcache_config` option to specify the Ehcache config file to use (where the default is "ehcache.xml" in your Rails config directory), and the :cache_name option to provide a custom name for your cache (the default is rails_cache). -In addition to the standard `:expires_in` option, the `write` method on this cache can also accept the additional `:unless_exist` option, which will cause the cache store to use Ehcache's `putIfAbsent` method instead of `put`, and therefore will not overwrite an existing entry. Additionally, the `write` method supports all of the properties exposed by the [Ehcache Element class](http://ehcache.org/apidocs/net/sf/ehcache/Element.html) , including: +In addition to the standard `:expires_in` option, the `write` method on this cache can also accept the additional `:unless_exist` option, which will cause the cache store to use Ehcache's `putIfAbsent` method instead of `put`, and therefore will not overwrite an existing entry. Additionally, the `write` method supports all of the properties exposed by the [Ehcache Element class](http://ehcache.org/apidocs/net/sf/ehcache/Element.html) , including: | Property | Argument Type | Description | | --------------------------- | ------------------- | ----------------------------------------------------------- | |