Add handler for change logical connection of optional parameters

[adpe]

Hi @abias

Here's my first solution to add the functionality, to add a node with a one-liner for system-context and page-context in parallel.

Without this functionality, you must add two separate lines. But then you have the problem, that if you're per example site-admin and the same time teacher in a course you'll see two nodes.

This change should not break existing entries.

Thanks to look at it Adrian

[abias]

Thank you very much, Adrian, for this pull request!

I hope that I will be able to look at it during the next few days.

Cheers, Alex

[abias]

Hi Adrian,

thank you very much again for this pull request.

Your implemented solution worked at first sight and I was about to merge it.

However, after sleeping over it, I decided that it isn't the way to go because:

• your implementation also handled the language setting by the logical connection operator, but this appeared as unnecessary at second sight
• your implementation connected all 4 optional settings one by one with binary OR. If we would have had a node with a broken URL (resulting in $nodevisible = false) but with the correct language, this node would have become visible. This must not happen
• after talking to two other persons, I had to realize that adding a omissible first parameter as logical connection operator will be difficult to understand

So I ended with with a reimplementation on https://github.com/moodleuulm/moodle-local_boostnavigation/commit/207ffdd5968216282cd4d85930d97985e4b9f779 where I gave you the credits for the idea.

That's why I am closing this PR withing merging it.

Cheers, Alex