安装Joomla扩展JCH后出现非对象属性获取通知的技术问询

What's the Issue? #

After installing the JCH extension, you're seeing this PHP notice pop up:

Notice: Trying to get property of non-object in ../libraries/src/UCM/UCMType.php on line 169

The Good News First #

Per the JCH extension developer, this is not a problem with the JCH extension itself—it's a small quirk in Joomla's core code. Even better: it won't affect how the JCH extension functions at all.

Why This Happens #

Let's break down the problematic code. The error hits on line 169 of UCMType.php:

$tableNameFromType = $tableFromType->special->prefix . $tableFromType->special->type;

Here's the full surrounding function context:

public function getTypeByTable($tableName) {
    $query = $this->db->getQuery(true);
    $query->select('ct.*');
    $query->from($this->db->quoteName('#__content_types', 'ct'));
    // $query->where($this->db->quoteName('ct.type_alias') . ' = ' . (int) $typeAlias);
    $this->db->setQuery($query);
    $types = $this->db->loadObjectList();

    foreach ($types as $type) {
        $tableFromType = json_decode($type->table);
        $tableNameFromType = $tableFromType->special->prefix . $tableFromType->special->type;
        if ($tableNameFromType === $tableName) {
            return $type;
        }
    }

    return false;
}

The bug stems from this: json_decode($type->table) might return null or a non-object (if the table field in the #__content_types database table has invalid JSON, or is empty). When that happens, trying to access $tableFromType->special throws the notice because $tableFromType isn't the object the code expects.

How to Handle It #

Since this doesn't break your JCH extension, you have two straightforward options:

• Hide the notice (easiest fix): Head to your Joomla backend's Global Configuration, find the "Error Reporting" setting, and set it to "System Default" or "None". This will suppress non-critical PHP notices like this one without affecting functionality.
• Patch the core code (advanced): If you want to fix the root cause, add a validation check right after the json_decode line to skip invalid entries:

  // Insert this after $tableFromType = json_decode($type->table);
  if (!is_object($tableFromType) || !isset($tableFromType->special)) {
      continue;
  }
  

  Note: Modifying Joomla core code means your change will get overwritten when you update Joomla, so the first option is usually the safer choice for most users.

内容的提问来源于stack exchange，提问作者GalanopD