Document::setData() should be nullable

[rgazelot]

I think that the method Document::setData($element) should accept a nullable value as the constructor does.

[antonkomarev]

This will require to change signature to public function setData(?ElementInterface $element) what will lead drop PHP7.0 support. Because nullable types are available since PHP7.1 only.

[rgazelot]

What about public function setData(ElementInterface $element = null)?

[antonkomarev]

By this way you will only be able to do $document->setData(); but not $docuemnt->setData(null). Try it yourself.

[rgazelot]

I agree that PHP7.1 nullable argument are by far the best way to do it, but I'm ok with the PHP7.0 compatibility. Maybe just keep in mind this thing for a future PHP7.1 support?

[franzliedke]

For PHP 7.0 compatibility, we would probably need a clearData() function then.

[f3ath]

What about creating a special case: function setNullData(): void?

[antonkomarev]

Before implement any of proposed ways we need to define concrete use case for it.