TYPO3.Fluid

Hi all,
i am having trouble to get an empty array in a shorthand if condition.

The situation is the following:
I have an Input field which can be required or optional, depending on a checkbox in Backend.

In my Template i tried this;

additionalAttributes="{f:if(condition: '{field.mandatory}', then: '{required: 1}', else: '{}')}"

The "then"-case works fine, i am getting the attribute required="1" as expected.

The problem is, that the '{}' in the else-case returns an empty string, not an empty array. Then i get an exception, because additionalAttributes expects an array.
I tried a couple of things to get this to work like {0: null}, {\'\'} or {null} but i always get either an empty string or an non-empty array like array(0 => null).
The last one is not an option because it would result in an attribute "0" in the html tag.

Me and my colleagues came up with a view workarrounds:

1) Assign an empty array to a variable in the controller and use this variable in the template.
- This is in my case not an option because i am extending an TER extension and dont want to override its controller.

2) Add an "Empty-Array-Getter" to the Model like getEmptyArray which returns an empty array.
- This is a possibility, because i am extending the model as well, but... urghs ;)

3) Write a viewhelper that adds an empty array to the templateVariableContainer.
- This is probably the best workaround and i am using this for now.

The viewhelper looks simply like this:

class EmptyArrayViewHelper extends \TYPO3\CMS\Fluid\Core\ViewHelper\AbstractViewHelper {
public function render() {
$this->templateVariableContainer->add('emptyArray', array());
return NULL;
}
}

So i use can {emptyArray} in my template now after calling the viewhelper:
<fx:EmptyArray />
...
additionalAttributes="{f:if(condition: '{field.mandatory}', then: '{required: 1}', else: '{emptyArray}')}"

Did we miss anything here or is there no other way to solve this scenario?

Thanks and regards,
Thomas