Unique keys#

There are several cases where you may want to generate a unique key. For example:

• populate ID attribute in your HTML output
• key for partial cache

This can be done simply by including following code in your template:

$DataObject.UniqueKey

getUniqueKey method is available on DataObject so you can use it on many object types like pages and blocks.

Customisation#

The unique key generation can be altered in two ways:

• you can provide extra data to be used when generating a key via an extension
• you can inject over the key generation service and write your own custom code

Extension point#

cacheKeyComponent extension point is located in DataObject::getUniqueKeyComponents. Use standard extension flow to define the cacheKeyComponent method on your extension which is expected to return a string. This value will be used when unique key is generated. Common cases are:

• versions - object in different version stages needs to have different unique keys
• locales - object in different locales needs to have different unique keys

Custom service#

UniqueKeyService is used by default but you can use injector to override it with your custom service. For example:

SilverStripe\Core\Injector\Injector:
  SilverStripe\ORM\UniqueKey\UniqueKeyService:
    class: App\Service\MyCustomService

Your custom service has to implement UniqueKeyInterface.