Block Plugin Derivatives Discovery

Question

I need some help with my code. I am creating blocks dynamically using the plugin derivatives. I store some form data in a database table, then I display it in each block separately, depending on it's derivative id. My issue is: while, I do obtain all the individual blocks on a full clear cache, in the "Place Block" section, it's not there when I submit the form, basically, I would like the form submit function to trigger the derivative creation and it's discovery. Any suggestions appreciated.

Here's my Plugin Derivative code:

<?php

namespace Drupal\simpleads\Plugin\Derivative;

use Drupal\Component\Plugin\Derivative\DeriverBase;

class SimpleAdsBlock extends DeriverBase
{
    public function getDerivativeDefinitions($base_plugin_definition)
    {
        $query = \Drupal::database()
            ->select('simpleads_blocks', 'sb')
            ->fields('sb');
        $results = $query->execute()->fetchAll();

    foreach ($results as $result) {
        $this->derivatives[$result->bid] = $base_plugin_definition;
        $this->derivatives[$result->bid]['admin_label'] = $result->name;
    }

    return $this->derivatives;
    }
}

Answer 1

Copied from BlockContent::postSave():

// Invalidate the block cache to update custom block-based derivatives.
\Drupal::service('plugin.manager.block')->clearCachedDefinitions();