Implements accessing the UUIDs of a config items by tag reference

[ndejong]

Raised as issue #2664
Discussed in forum here

[ndejong]

Even tried creating a new branch to prevent those previous commits getting tangled up with this PR here - oh, git...

[fabianfrz]

should be done for a single element

[ndejong]

This updated diff makes it more explicit about there the uuid string is coming from - also adds a break once the uuid is found since we don't need to keep searching and can skip to the next

[AdSchellevis]

@ndejong if we add the attributes to the object, would that be sufficient for you? I'm not sure we should add an extractor for all uuids if most use-cases need the uuid of the item traversing.

[ndejong]

@AdSchellevis - I'm probably happy with any solution that is clear and easy to use.

If step back for a moment and consider why I wrote an extractor - As a relative newbie in the OPNsense codebase I felt like I wanted a solution that made the templates easier to write and understand. To get there I first dug through other templates and then through code to discover the data-structures inside the template helpers at which point it did not occur to me that I could simply use the item object itself as the comparator as @fabianfrz pointed out in the Nginx work around - my extractor uses the same approach.

The idea of injecting a special __uuid__ attribute into each item certainly works, perhaps the comment I'd make is that, again as a newbie it took me until I discovered where the template helper was and then finding a way to observe the data-structures inside that the __uuid_tags__ and __uuid__ elements became apparent - it was all a bit magic :) and so I wonder if the per item __uuid__ attribute will be too much magic and/or get confused with the existing __uuid__ element that feels like it could have been called __uuids__ (with the "s")

I'm perhaps biased here, but I feel like the explicit function that does what it says getUUIDs() makes it easier for the next plugin developer that comes stumbling along.

Totally your call.

[fabianfrz]

@AdSchellevis the uuid as a property would be exactly what I need. be careful because you may overwrite data. In PHP i get it as [(at) attibutes]["uuid"]. The advantage is, that an @ cannot be a valid XML tag.

[AdSchellevis]

@fabianfrz I know, As soon as I have a proper fix, I'll post it in the issue #2664 and close this one when done.

[AdSchellevis]

@ndejong @fabianfrz this 3add6c7 should do the trick.

To use a uuid, just use something similar to:

  {{item['@uuid']}}

[ndejong]

Most excellent indeed

[AdSchellevis]

@ndejong can I close this pull request?

[ndejong]

@AdSchellevis yes please do