After installing the patch, the following notice messages appear:

Notice: Only variables should be passed by reference in C:\xampp\htdocs\bugtesting5\joomla\plugins\content\contact\services\provider.php on line 38

Notice: Only variables should be passed by reference in C:\xampp\htdocs\bugtesting5\joomla\plugins\content\emailcloak\services\provider.php on line 37

And so on.

Doesn't seem to be a problem of this patch, but an underlying problem.
Assigning to $container->get(DispatcherInterface::class) a separate variable, solves this problem.

Does the same issue happen also on the 4.4-dev branch. For me it gives the impression that you somehow screwed up Joomla. But the message is definitely not related to the current pr.

is definitely not related to the current pr

I have also encountered this problem before.

[EDIT: PHPStorm reports 'Only variables can be passed by reference']

But the message is definitely not related to the current pr.

Oops, I tested in Joomla 5.

I have tested this item ✅ successfully on c1ec401

I have tested this item ✅ successfully on c1ec401

RTC

I'm not so happy with this, a plugin is normally not a thing which is used for translation, I also would move the tmpl from the plugin to layouts which is more the character then a "full" template at least in my understanding.

This here helps to ease the transition. At the end of the day the template files should work the same, regardless if they are used in views, modules, plugins and layouts. So this here is needed to provide a similar context in all of them. There are legit use cases where template files are used in plugins. So this is fine for the current architecture. If one some point we harmonize the whole code base then it will be even easier when all the template files use the same functions.

polluting the namespace/class for all plugins doesn't make sense anyway, better use a trait and the plugin that really needs this functionality should use it.

Why is it only this plugin that is updated and not all the others

Also this doesn't look like a proper "template engine" when you have to write the code your self:
https://github.com/Digital-Peak/joomla-cms/blob/c1ec40129dc59e9b21db1d64ab8ab7215fa66be6/plugins/installer/packageinstaller/src/Extension/PackageInstaller.php#L53-L55

and don't have at least a render() function

and don't have at least a render() function

Hey does such a render function look like?
Isn't this a proven technique in Joomla to render? See among others.

https://github.com/Digital-Peak/joomla-cms/blob/c1ec40129dc59e9b21db1d64ab8ab7215fa66be6/plugins/content/vote/src/Extension/Vote.php#L118-L121

Why is it only this plugin that is updated and not all the others

I will do this in 5.0 once it is upmerged, similar to #41079 and #41063.

Also this doesn't look like a proper "template engine" when you have to write the code your self

As I said, this pr is made for the current architecture. If you want to change it go ahead and make a pr. This here is fine for what we have now. Not saying it is the gold solution.

@brianteeman here we go #41092.

thanks - I guess I am/was confused why you change one here for 4.4 and all the others for 5.0