SilverStripe Cache Include

Template caching based on urls not DB queries.

Features

• Cache keys are built from information available in request object (means no DB calls)
• Invalidation hooks for when DataObject's are modified
• Uses doctrine/cache library, providing many cache backends
• Uses Symfony Expression language for fine-grained invalidation control
• Support for <% cache_include 'TemplateName' %> syntax in templates
• Support for <% cache %><% end_cache %> syntax in templates
• A full request cache that includes the ability to substitute security tokens
• Highly customisable
• Sets request header when cache is hit for easier testing e.g hit at Thu, 03 Mar 2022 14:23:41 -0600

Installation

$ composer require heyday/silverstripe-cacheinclude:~5.0

How to use

Enabling

To be able to invalidate caches from DataObject writes, add the InvalidationExtension:

1. C te a config file mysite/_config/caching.yml
2. Add the following to the yml file

---
After: 'silverstripe-cacheinclude/*'
---
SilverStripe\ORM\DataObject:
  extensions:
    - Heyday\CacheInclude\SilverStripe\InvalidationExtension

Template Usage

Cache a section of a template:

<% cache 'SomeCacheBlock' %>
<% loop ExpensiveSet %><% end_loop %>
<% end_cache %>

Cache an included template (assumes a cache block config name of SomeTemplateName):

<% cache_include 'SomeTemplateName' %>

Cache an included template with a different cache block config name:

<% cache_include 'App\Includes\SomeTemplateName', 'CacheBlockConfigName' %>

Cache block config

For each cache block that is used, you need a corresponding config provided to CacheInclude.

The following is an example of a config for SomeCacheBlock and AnotherCacheBlock:

mysite/_config/caching.yml

---
After: 'silverstripe-cacheinclude/*'
---
Injector:
  CacheIncludeConfig:
    class: Heyday\CacheInclude\Configs\ArrayConfig
    properties:
      Config:
        SomeCacheBlock:
          context: full
          contains:
            - MyDataObject
        AnotherCacheBlock:
          context: no
          expires: +1 hour

Configuration options

Key creation options:

context

Context is a method to tell the key creator what information about the request to include in the created key.

Possible values:

• no
  • Key created is independent of the request
• host
  • Key created with the host name, useful for when using Subsites or multiple base domains
• page
  • Key is created based on url, but not including GET variables
• full
  • Key is created based on url, including GET variables

expires

Possible values:

• (string)
  • A string to pass into strtotime e.g. '+1 hour'
• (int)
  • A number of seconds

member

Possible values:

• true
  • Will create a new cache per logged in member
• any
  • Will create a new cache members as a group (and another key when a person is not logged in)

versions

Possible values:

• (int)
  • Set this to an integer to make the specified number of versions of the cache

This is useful for when a cache block contains random content, but you still want caching.

e.g. set to 20 to get 20 (potentially) different version of a cache block.

Cache invalidation options

contains

• (array)
  • An array of class names that if a record saved matches the cache will invalidate

invalidation_rules

• (array)
  • An array of rules written in the available expression language. If a rule is matched the cache will invalidate

The Expression Language is provided by Symfony, but also has the following available:

Variables

• item
• action

Functions

• list()
• instanceof()

Theses can be used to do the following:

  invalidation_rules:
    - "instanceof(item, 'CreativeProfile') and item.ID in list('CreativeProfile').sort('Created DESC').limit(4).getIDList()"

Full request caching

CacheInclude comes with a RequestCache service that can be added to cache full request objects for use in high load sites.

Enabling

To enable the full request cache, the RequestCacheMiddleware needs to be applied and a Global config block needs to be created:

---
After: '#cacheinclude'
---
SilverStripe\Core\Injector\Injector:
  CacheIncludeConfig:
    class: Heyday\CacheInclude\Configs\ArrayConfig
    properties:
      Config:
        Global:
          contains:
            - SilverStripe\CMS\Model\SiteTree
          context: full
          expires: '+ 1 hour'
---
After: '#coresecurity'
---
SilverStripe\Core\Injector\Injector:
  SilverStripe\Control\Director:
    properties:
      Middlewares:
        RequestCacheMiddleware: '%$RequestCacheMiddleware'

Note: the After: condition in the above example is important. Without it, the middleware that handles request caching will run before SilverStripe's authentication middleware - meaning that the current user (stored in the session) isn't available. This could result in cache contamination between users, or between guests & registered users.

Full request caching increases performance substantially but it isn't without a cost. It can be hard to configure, as there are numerous cases where you don't want to either cache a request or alternatively serve a cached request.

To help in this there is quite a bit you can do out of the box to configure the way that caching is handled.

The following gives some demonstration of how to configure things and what you can do:

Injector:
  RequestCacheMiddleware:
    class: 'Heyday\CacheInclude\SilverStripe\RequestCacheMiddleware'
    constructor:
      0: '%$CacheInclude'
      1: '%$CacheIncludeExpressionLanguage'
      2: 'Global'
    properties:
      Tokens:
        - '%$SilverStripe\Security\SecurityToken'
      SaveExcludeRules:
        - 'request.getUrl() matches "{^admin|dev}"'
      SaveIncludeRules:
        - "request.httpMethod() == 'GET'"
        - 'response.getStatusCode() == 200'
      FetchExcludeRules:
        - 'request.getUrl() matches "{^admin|dev}"'
      FetchIncludeRules:
        - "request.httpMethod() == 'GET'"

As you can see above there are some variables made accessible to you in the expression language.

The following is made available in the "Save" rules:

• request
• response
• member
• session

The following is made available in the "Fetch" rules:

• request
• member
• session

Additional variables can be provided through the injector system.

Injector:
  RequestCacheMiddleware:
    properties:
      ExtraExpressionVars:
        'hello': 'Something'

Customisation

Because of the heavy usage of dependency injection and the SilverStripe Injector component, most parts of CacheInclude can be completely customised by replacing the standard classes with ones of your own.

Key Creators

CacheInclude comes built in with one key creator Heyday\CacheInclude\KeyCreators\ControllerBased. This key creator makes keys based on the config supplied in yaml, the current request and the environment.

You can create your own key creators by extending the KeyCreatorInterface and specifying the creator's service name from the template.

<% cache 'SomeBlock', 'MyKeyCreator' %>
Some content
<% end_cache %>

class MyKeyCreator implements \Heyday\CacheInclude\KeyCreators\KeyCreatorInterface
{
    public function getKey($name, $config)
    {
        return [
           'key',
           'parts'
        ];
    }
}

License

SilverStripe CacheInclude is released under the MIT license

Contributing

Unit Testing

$ composer install --prefer-dist --dev
$ phpunit

Code guidelines

This project follows the standards defined in:

• PSR-0
• PSR-1
• PSR-2

Run the following before contributing:

$ php-cs-fixer fix .