Teach civix about the mixin about civix

[colemanw]

@totten I'm confused about this. I don't see hardcoded references to specific mixins in civix. Doesn't it just scan civicrm-core/mixin for those? Why isn't this working?

[totten]

This issue should be fixed by d8e980e / v22.06.2.

@colemanw The list is mixin-backports.php. You may recall - the testing+metadata+requirements for backports are more fiddly/stringent than for regular code updates, and it's easier on my brain if that responsibility is split (ie civicrm-core drives new iterations of the mixins per SemVer; then civix decides backports).

The bit that might be surprising - civix currently wants mixin-backports.php to have a full list (even if you don't intend to use backports). It's easy to update. It would be nice to work better with non-backported mixins, though I'm not sure how easy it is to support both.

Question/aside: afform-entity-php@1 is provided by 5.50. Is that also the minimum to use it? Or does it also work on prior versions?

[colemanw]

@totten this mixin has a bit of a weird upgrade path:

• < 5.50 the mixin is not needed because core does the file scanning automatically
• >= 5.50 the mixin is required if you want to keep doing the file scanning

So for an extension to be compatible with all versions, it should add the mixin tag to info.xml and then provide an empty shim that does nothing, like this: https://github.com/eileenmcnaughton/deduper/pull/26/files

[totten]

@colemanw Re-reading, perhaps d8e980e wasn't the correct revision?

• That would have the effect of copying https://raw.githubusercontent.com/civicrm/civicrm-core/5.50.0/mixin/afform-entity-php@1/mixin.php (let's call it v1.0.0-real) into an extension.
• But any system which needs that revision already has it.
• The copied file only matters when running on older systems.
• Older systems should have https://raw.githubusercontent.com/colemanw/deduper/6791ae0b70db3790ac4508a69c54498c13dbf111/mixin/afform-entity-php%401/mixin.php (let's call it v1.0.0-null) (mostly so that they don't error-out on the missing file).

Additional question: for systems <5.50, how far back does it go? Like it's meaningful to use 1.0.0-null on, say, 5.30?

[totten]

There appears to be some afformEntity scanning code as far back as civicrm/civicrm-core@0406c8f#diff-b700bdf29c94b8c86727852b07277f33787500b5af297c2fc5c86105ec0edc50R191. So maybe the minimum is 5.31

[totten]

Aah, wait. The only behavior of v1.0.0-real is to subscribe to civi.afform_admin.metadata -- which won't be emitted on 5.31-5.49. v1.0.0-real and v1.0.0-null are both nullops. It shouldn't matter which variant we use for backport purposes.

The only difference is that v1.0.0-null provides better comments. We could add more comments to v1.0.0-real -- and then we don't need two versions of the file?