JHTMLBEHAVIOR-CLASS-001
JHtmlBehavior
JHtmlBehavior class name
JHtmlBehavior is a Joomla 3 global class. Joomla 4 still has an alias. Joomla 5 needs the Behaviour – Backward Compatibility plugin. Native Joomla 6 does not load that alias — you get Class "JHtmlBehavior" not found.
JHtmlBehavior → Joomla\CMS\HTML\Helpers\Behavior
What you will see
- Class "JHtmlBehavior" not found
- Class 'JHtmlBehavior' not found
- Failed to open stream: JHtmlBehavior
Symptoms people search
white screen after disabling compatibility plugin · class not found on Joomla 6 · works on Joomla 5 until I turn off backward compatibility
Replace this code
Swap JHtmlBehavior for Joomla\CMS\HTML\Helpers\Behavior.
Joomla 3
Remove or stop calling this
JHtmlBehavior::getInstance();
// or new JHtmlBehavior()Joomla 4 / 6
Use this instead
use Joomla\CMS\HTML\Helpers\Behavior;
// Call the namespaced class. Do not keep the J prefix.How to fix it
- 1Add a use statement for Joomla\CMS\HTML\Helpers\Behavior.
- 2Replace every JHtmlBehavior with the short class name from that use line.
- 3Disable Behaviour – Backward Compatibility on a Joomla 5 staging site. If it fatals, this class is still in the code.
Also known as
JHtmlBehavior · Joomla\CMS\HTML\Helpers\Behavior · class alias · J prefix
Related issues
- Joomla 3 → 4Joomla API
JRequest::getVar() and the whole JRequest API
JRequest::getVar() → $app->getInput()->get('id')
- Joomla 3 → 4Joomla API
JError / JException
JError::raiseError() → throw new RuntimeException() / try-catch
- Joomla 3 → 4Joomla API
isAdmin() / isSite()
$app->isAdmin() → $app->isClient('administrator') / isClient('site')
- Joomla 3 → 4Joomla API
Factory::getUri()
JFactory::getUri() → Uri::getInstance()
- Joomla 3 → 4Joomla API
Factory::getXml() / JXMLElement
JFactory::getXML() → SimpleXMLElement
- Joomla 3 → 4Joomla API
Factory::getEditor()
JFactory::getEditor() → Editor::getInstance()