Resolver

Overview

Time's Up utilizes cache-tags resolvers to periodically clear caches.

A resolver essentially does two things:

1. Defines a cache-tag name to be invalidated.
2. Defines a periodicity to invalidate that cache tag.

You may want to extend Time's Up with your own resolvers to implement custom periodicity.

Resolver Declaration

In order to decalre a new Resolver, you only needs 2 things

• Declaring your resolver in your very own module.services.yml and tag your service with timesup.periodicity_resolver.
• Create a service associated with the previous declaration on module.services.yml
  • Define a cache-tag name (will be prefixed with timesup:)
  • Define a periodicity logic to run the resolver

Example

To declare a new resolver that defines a cache-tag to clear content every day at midday, you can follow these steps:

1. Declaring your resolver in a services.yml file

my_module.services.yml

services:
  my_module.timesup.periodicity_resolver.daily_midday:
    class: Drupal\my_module\Timesup\Periodicity\DailyMiddayResolver
    parent: timesup.periodicity_resolver.base
    tags:
      - { name: timesup.periodicity_resolver, priority: 0 }

2. Create a new Resolver Class

my_module/src/Timesup/Periodicity/DailyMiddayResolver.php

<?php

namespace Drupal\my_module\Timesup\Periodicity;

/**
 * Will clear the cache-tags timesup_midday every day at midday.
 *
 * @internal
 */
final class DailyMiddayResolver extends PeriodicityBaseResolver {

  /**
   * The Cache tag name to invalidate.
   *
   * @string
   */
  const CACHE_TAG = 'midday';

  /**
   * {@inheritdoc}
   */
  public function shouldApply(): bool {
    // Code here your very own logic to run or not run the cache chear.
     
    // You can get the last run timestamp using.
    $last_run = $this->state->get($this->getLastRunKey());

    // From this last run, you can calculate the next desired occurence
    // and define the difference between now to run or not the invalidation.
  }
}

3. Use the defined cache-tag

You may now use the declared cache-tag timesup:midday anywhere you need it.