Joomla 4 - Check if Alias is Unique

Question

I'm trying to develop a Joomla 4 component and I almost completed it, but I have issues to save an item when the Alias is not Unique.

In the database, I've set up this:

CREATE UNIQUE INDEX aliasindex ON rwl35_rwlevents (alias); In the Model (administrator/components/com_rwlevents/src/Model), I have this:

protected function prepareTable($table)
{
    $date = Factory::getDate()->toSql();

    $table->name = htmlspecialchars_decode($table->name, ENT_QUOTES);
    $table->check();
    $table->generateAlias();

}

Then, in the EventTable.php file, (/administrator/components/com_rwlevents/src/Table)

I have this code:

public function check()
{

    try
    {
        parent::check();
    }
    catch (\Exception $e)
    {
        $this->setError($e->getMessage());

        return false;
    }
    // Check the publish down date is not earlier than publish up.
    if ($this->publish_down > $this->_db->getNullDate() && $this->publish_down < $this->publish_up) {
        $this->setError(Text::_('JGLOBAL_START_PUBLISH_AFTER_FINISH'));

        return false;
    }

    // Set publish_up, publish_down to null if not set
    if (!$this->publish_up) {
        $this->publish_up = null;
    }

    if (!$this->publish_down) {
        $this->publish_down = null;
    }

    $this->alias = trim($this->alias);
    if (empty($this->alias))
    {
        $this->alias = $this->name;
    }
    $this->alias = JFilterOutput::stringURLSafe($this->alias);
    return true;
}

Then, In the same file, I have a function to generate the Alias:

public function generateAlias()
{
    if (empty($this->alias))
    {
        $this->alias = $this->name;
    }

    $this->alias = ApplicationHelper::stringURLSafe($this->alias, $this->language);

    if (trim(str_replace('-', '', $this->alias)) == '')
    {
        $this->alias = Factory::getDate()->format('Y-m-d-H-i-s');
    }

    return $this->alias;
}

But in the Admin, when I try to save an item with an Alias that already exists in the Database, I have:

Duplicate entry 'concert-au-3-arena' for key 'aliasindex'

How can I code this to say: "if this Alias already exists, then, do this..."?

Answer 1

I finally "partially" solved this by moving a piece of code, and replacing the date by an increment :

    public function check()
    {

        try
        {
            parent::check();
        }
        catch (\Exception $e)
        {
            $this->setError($e->getMessage());

            return false;
        }

                // Check the publish down date is not earlier than publish up.
                if ($this->publish_down > $this->_db->getNullDate() && $this->publish_down < $this->publish_up) {
                    $this->setError(Text::_('JGLOBAL_START_PUBLISH_AFTER_FINISH'));

                    return false;
                }

                // Set publish_up, publish_down to null if not set
                if (!$this->publish_up) {
                    $this->publish_up = null;
                }

                if (!$this->publish_down) {
                    $this->publish_down = null;
                }

    jimport('joomla.filter.output');
    if (empty($this->alias)) {
        $this->alias = $this->name;
    }
    $pk = $this->id;
    if (empty($pk)) {
        $pk = 0;
    }

            $originAlias = $this->alias;

    $this->alias = EventHelper::stringURLSafe(trim($this->alias));

         if (empty($this->alias)) {
             $this->alias = $originAlias;
             $this->alias = EventHelper::replace($this->alias);
             $this->alias = JFilterOutput::stringURLSafe($this->alias);
         };

    $db = Factory::getDbo();
    $query = $db->getQuery(true);
          $query->select('COUNT(*)')
        ->from('#__rwlevents')
        ->where('`alias` = ' .$db->Quote($this->alias))
        ->where('`id` <> '.$pk);
    $db->setQuery($query);
            $newalias = $this->alias;
    $count = $db->loadResult();
            $increment = $count + 1;
            if (!empty($count) AND $count >= 1) {
             $this->alias = EventHelper::replace($newalias);
             $this->alias = JFilterOutput::stringURLSafe($newalias).'-'. $increment;
    }
    return true;
}

The only issue I have now is that when I have more than 1 Dupliacte, the Alias become something like this :

concert-au-3-arena-2-2

concert-au-3-arena-2-2-2

concert-au-3-arena-2-2-2-2