Delete row from custom made SQL when deleting article in Joomla

Question

I´m still new to Joomla and to coding SQL.

I was thinking about how I should manage a big system I made with information that is saved in a sql table, that contains some user input and the "id" of an article.

If you or another administrator deletes an article, I guess I have to delete the row containing that articles id in my custom sql table too?

Is there a way to make a script that gets executed every time an article gets deleted? that way I could maybe get the article id and then remove it from my custom table.

How do you guys handle your custom sql tables that contains references to articles or users in Joomla?

Answer 1

Create a plugin with onContentAfterDelete event. Basic example:

<?php
defined('_JEXEC') or die;

use Joomla\CMS\Factory;
use Joomla\CMS\Plugin\CMSPlugin;

class PlgContentExample extends CMSPlugin
{
    public function onContentAfterDelete($context, $item)
    {
        // Check that the deleted item is an article.
        if ($context !== 'com_content.article')
        {
            return true;
        }

        $db = Factory::getDbo();
        $query = $db->getQuery(true)
            ->delete($db->quoteName('#__customtable'))
            ->where($db->quoteName('article_id') . ' = ' . (int) $item->id);
        $db->setQuery($query);

        try
        {
            $db->execute();
        }
        catch (\RuntimeException $e)
        {
            // Informational log only
        }
    }
}

Replace #__customtable with the name of your table and article_id with the column that holds article IDs.

Docs:

Plugin/Events/Content

Creating a content plugin

Plugin Development