How to Create Your Own Addon

Anyone interested can write their own addon. The main rule is to know at least the basics of working with PHP code (ideally, Object-Oriented Programming). In the repository, there is an example of a simple addon, let’s break it down:

ExampleAddon.php

<?php declare(strict_types=1);

final class ExampleAddon extends AbstractAddon
{
  public const PACKAGE_ID = 'Optimus:ExampleAddon';

  public static array $events = [
    self::HOOK_EVENT,
  ];

  public function __invoke(AddonEvent $event): void
  {
    if ($event->eventName() !== self::HOOK_EVENT)
      return;

    IntegrationHook::add(
      'integrate_theme_context', self::class . '::hideSomeTopicsFromSpiders#', false, __FILE__
    );
  }

  public function hideSomeTopicsFromSpiders(): void
  {
    if (empty(Utils::$context['topicinfo']))
      return;

    if (Utils::$context['topicinfo']['locked'] || Utils::$context['topicinfo']['num_replies'] < 2) {
      Utils::$context['meta_tags'][] = ['name' => 'robots', 'content' => 'noindex,nofollow'];
    }
  }
}

The addon class must extend the existing abstract class AbstractAddon and have a constant PACKAGE_ID that specifies the package identifier. If the addon is intended to connect with an existing modification, its ID can be found in package-info.xml under the id node — for example, <id>Bugo:Optimus</id>.

If it is a built-in Optimus addon, the identifier starts with Optimus:, followed by the name of the current class. If your addon is not related to any existing modification but you want it to work with Optimus, use a similar identifier.

Next, in the static property $events, you specify an array that returns the events supported specifically by this addon. self::HOOK_EVENT is a universal event designed for interaction with SMF hooks. An example of working with it is provided in the __invoke method.

Using IntegrationHook::add, we specify the hook we need and link it to a method within the addon class.

Then, the linked method performs its task. Specifically, in this addon — ExampleAddon — a meta tag <meta name="robots" content="noindex,nofollow"> is added to the pages of blocked topics, as well as to topics with fewer than two replies. If you need such an addon, save its code in the corresponding file ExampleAddon.php and place it in the Sources/Optimus/Addons directory. You won’t need to enable anything separately; it will work immediately.

All available addons operate on the same principle.

Addon Settings

If your addon has its own options, it can get its own collapsible settings block on the Addons tab of the Optimus admin area instead of adding its options to the general settings pages.

To do this, implement the HasSettingsInterface interface in your addon class:

final class IndexNow extends AbstractAddon implements HasSettingsInterface
{
  public function getSettings(): array
  {
    return [
      [
        'text',
        'optimus_index_now_key',
        'size'    => 128,
        'subtext' => Lang::getTxt('optimus_index_now_key_subtext'),
      ]
    ];
  }

  public function saveSettings(): void
  {
    // Additional actions when saving the settings, if necessary
  }
}

The getSettings() method must return the addon options in the standard SMF format (the same as in the integrate_general_settings hook). The saveSettings() method is optional and is only needed for additional actions when saving — for example, creating auxiliary files.

A short description of the addon displayed in the list can be provided via the optimus_addon_<lowercase_addon_name>_desc string in the language file.