This namespaces the JHtml helpers as agreed by Production. Fixes #28249

• Also fixes a bug in the error_login.php file of atum that I discovered whilst doing this where we could double register a html service

Summary of Changes

Namespaces JHtml classes. Note the two classes that are new for J4 (workflowstages and draggable do not have namespace mappings created as they are new for j4)

Testing Instructions

Ensure CMS works as before in a variety of frontend and backend views

If you are technical review class names make sense - as they aren’t tied to the name being called they can be made longer without any affect

Documentation Changes Required

Yes. If you are overriding JHtml methods you can no longer use \Joomla\CMS\HTML\HTMLHelper::register() you now must instead use

\Joomla\CMS\HTML\HTMLHelper::getServiceRegistry()->register('jquery', 'MyCustomClass', true);

The last parameter $replace is the important part :) Note that this means you can only override the entire Helper. You can't overload a specific function after this change. In the two cases where people regularly do this in the ecosystem (bootstrap and jquery) this isn't really an issue:

• In JQuery there are only two methods - the second a helper for ajax and it's a minor thing to have to duplicate and I don't see any real issues forthcoming as jQuery is now fairly static
• In Bootstrap whilst there are lots of methods they output html specific to the bootstrap version so you'd need to have overridden them anyhow