side effects of 'each' and 'options' together

[Kanaye]

Look at the selects or click the "reset" button and look at the browsers console 😞.
https://jsfiddle.net/h19tftc7/3/

[Kanaye]

Hmm that's an interesting problem and hard to explain (at least for me).
Let's try it:
We are calling the options-preprocess-function for each cycle of the each-data-query.
And we are adding the caption every time as a child-element (here).
But we are only testing for data-role="header" the first time (here) so the other children don't get rendered as header but as normal children.
Here the example updated to show that behaviour.

We can't skip the execution of preprocess cause the options parameter could be a property of the each-data-query. Also we can't "kill" the _headers as we need them in the update-function.

I don't have a clean solution (yet).

[Kanaye]

Finally fixed this 🎉.

That was harder than I imagined when I started to work on this issue again a month ago.
Had 3 nearly working approches, one of them totally overengineered 😆

The acctual fix will have some negative impact on performance because we are now cloning the _template for each iteration in the each-data-query to the iterations state.

I think it's not that big of deal bacause the VirtualElements aren't that hard to clone and we currently have time/memory-havier things to work on, but I have it on my things-to-think-over-again-list.

Also I think a a little slower but working approach should be prefered over a bugged version.

Just as some things that should be noted in my opinion.