Add in Deprecation warnings on Cache functons

[seamuslee001]

Overview

This adds deprecation warning notices on these functions as they aren't used by Core now

The following functions are deprected

CRM_Core_BAO_Cache::setItem
CRM_Core_BAO_Cache::getItem
CRM_Core_BAO_Cache::getItems
CRM_Core_BAO_Cache::deleteGroup

Developers shoud instead use something like the following instead

Civi::cache()->set()
CIvi::cache()->get()
Civi::cache()->flush()

If a developer wants to have their own Cache Group which might be useful if you are wanting to manage your cached data separate to the rest of data in a short cache then the following should be added in your extension.php file

/**
 * Implements hook_civicrm_container().
 */
function extensionshortname_civicrm_container(\Symfony\Component\DependencyInjection\ContainerBuilder $container) {
  $container->setDefinition("cache.{groupname}", new Symfony\Component\DependencyInjection\Definition(
    'CRM_Utils_Cache_Interface',
    [
      [
        'name' => '{cache group name}',
        'type' => ['*memory*', 'SqlGroup', 'ArrayCache'],
        'withArray' => 'fast',
      ],
    ]
  ))->setFactory('CRM_Utils_Cache::create');
}

Then in your code use the following style of code

Civi::cache(<groupname>)->set()
Civi::cache(<groupname>)->get()

For more read https://docs.civicrm.org/dev/en/latest/framework/cache/

Before

No Warning

After

Warning

ping @eileenmcnaughton

[civibot]

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[eileenmcnaughton]

@seamuslee001 guess we'd better stop testing it :-)

[seamuslee001]

@eileenmcnaughton i have updated the tests to be most appropriate i think

[eileenmcnaughton]

@seamuslee001 I'm ok with merging this if it passes but can you update the summary to list what is deprecated & what people should do instead for the release notes?

[seamuslee001]

done @eileenmcnaughton

[eileenmcnaughton]

@seamuslee001 thanks - I'll add a link to https://docs.civicrm.org/dev/en/latest/framework/cache/ above