Custom category attributes don't show after upgrading to Magento 2.1.0

[JacobDrummond]

Preconditions

1. PHP 5.6.16
2. MySQL 5.6.21-log
3. Magento 2.1.0
4. Nginx 1.4.6

Steps to reproduce

1. Install Magento 2.0.2
2. Create custom category attributes using in an InstallData/UpgradeData class.
3. Confirm custom attributes show in the category form in Magento 2.0.2
4. Upgrade to Magento 2.1.0

Expected result

1. Custom category attributes show in the category admin form, as they did in 2.0.2

Actual result

1. The custom attributes still appear in the eav_attribute_* tables
2. However, custom category attributes don't show in the category admin form. Only the Magento attributes show.

[mhauri]

Same here.

Creating custom attributes for Products and Categories, only show up for Products but not in Categories. As some imports will create both Product and Category attributes, it will be painful if they aren't visible in the admin backend.

[JacobDrummond]

Thank you for confirming, @mhauri.

Did your custom attributes show in admin forms in earlier versions of Magento 2?

[mhauri]

@JacobDrummond yes they did, it wasn't a problem in 2.0.7.

[mrkhoa99]

@JacobDrummond , @mhauri As far as I know, from Magento 2.1, all category attributes are loaded via UI component. You can read more here:
http://magento.stackexchange.com/questions/127709/magento-2-1-how-to-create-category-attrbute-programmatically
http://magento.stackexchange.com/questions/129977/create-multiselect-with-source-model-in-ui-component

[mhauri]

@mrkhoa99 saw that to, but this can't be the way to go, how do you handle attributes created by an import. This would mean every time the import creates an attribute I have to update my codebase to make them visible. Also it works fine in Products, so why handle them differently.

For me this is still a bug and not a feature.

[JacobDrummond]

I agree with @mhauri: the whole point of EAV attributes is they can be determined at runtime.

What is the rationale for using hardcoded UIComponents to build EAV forms?

[JacobDrummond]

Hi @veloraven,

After reading @mrkhoa99's comment, it appears this bug is intended as a feature.

Two things:

• This feature breaks mission-critical functionality for those upgrading to Magento 2.1.0
• It does not appear to be in the 2.1 release notes.

Are release notes intended to be exhaustive? If not, how would you recommend third-party developers become aware of changes like this?

[alankent]

I am not an expert here, but that has never stopped me responding before! I would expect you should be able to upgrade from 2.0 to 2.1 without stuff disappearing. I don't know the details of why this one was changed. Either something was broken, or if we changed something then the upgrade script should migrate the data. In either case having things disappear from the form "sounds like a bug". But I don't know the details here so I may have to eat my hat.

[JacobDrummond]

Hi @alankent,

Adding Category attributes pre-2.1.0

1. Create category attribute in an UpgradeData file, just like Magento_Catalog does.
2. New attribute shows in admin forms simply by being present in Magento_Eav's tables.

Adding Category attributes post-2.1.0

1. Create category attribute in an UpgradeData file, just like Magento_Catalog does.
2. Register the new attribute in module's XML, by extending category_form.xml.
3. New category attribute shows in admin forms.

Upgrade problems

1. Pre 2.1, third-party developers created category attributes the first way. Client's input data, and everyone was happy.
2. Magento 2.1 introduced category_form.xml, yet it didn't appear to be in the 2.1 release notes. There was no XML-generation script to automatically publish custom EAV definitions to the right XML files in php magento setup:upgrade.
3. All custom category attributes disappeared from admin forms. Clients complained that they couldn't edit custom attributes anymore.

Architecture problems

• The whole point of EAV is you can change attribute definitions at run-time, as opposed to write-time.
• Product admin forms implement EAV perfectly. When you alter a product attribute definitions, the changes propagate immediately.
• By contrast, category attributes must be hard-coded in category_form.xml. This goes against EAV's ethos.
• Many people have complained about this architectural decision. For example, here and Magento CE 2.1 Not able to add attribute to category #5438.

As VP of Architecture, what do you think Magento's EAV strategy should be?