Integrate Xprofile Custom Fields into core

[Venutius]

BuddyPress Xprofile Custom Fields has been closed, this means 6.000 users will be without support and also means these xProfile options will not be available to new users. I suggest we should integrate the features of this plugin into core to ensure ongoing support of these features.

​https://wordpress.org/plugins/buddypress-xprofile-custom-fields-type/

Since the code is mature, it should be pretty straightforward to add to core, with most updates purely required to bring the code up to date.

[DJPaul]

Without commenting whether we want to provide support for a specific abandoned plugin, at a glance, I think the project could benefit from these field types:
(items marked with a * mean I think we can be 100% backwards compatible with this plugin)

• Colour*
• Extend the existing Number field to...
  • support a range of options, e.g. integers only.
  • support a min/max range.
• Email* (input type=email)
• [Multi-] Select for custom post type (e.g. pick a post?)
• [Multi-] Select for custom taxonomy (e.g. pick a favourite tag?)
• Slider* (HTML5 range input)

I think these are already implemented or too similar to existing generic field types:

• Birthdate
• Checkbox Acceptance
• Date Picker
• Web (URL)

I think these would be not trivial to implement well, or be a bad fit:

• File (upload)
• Image (upload)

[DJPaul]

For the "already implemented" fields, we might be able to shim the field type names internally and have them treated as aliases for the internal field types. That is, if that's something we want to do. I don't think we'd gain 100% compatibility but it might be close enough to not be useless?

[Offereins]

So apparently the plugin mentioned is recently ​forked twice (!), providing backwards compatibility for previous users of the plugin. This means you can either turn to the ​Buddypress XProfile Custom Field Types Reloaded by @seventhqueen or to ​BuddyPress Xprofile Custom Field Types by @buddydev to continue using these profile field types.

However, the question still remains whether some (or all) of these profile field types should be integrated in core, given their (relative) popularity among users of the XProfile component. I'd say yes, BuddyPress would definitely benefit from providing more profile field types.

In the context of connecting members with posts or taxonomy terms though, I'd like to shamelessly plug my ​BP XProfile Relationship Field plugin, which does this and more. Although it lacks proper support for working with huge numbers in dropdowns (select2 vs chosen vs ?), there is additional developer logic in place to create custom member-object relationships, for example member-member, member-media, etcetera. Perhaps that is also a direction BuddyPress can head into when it comes to easing the extension of profile fields possibilities.

[DJPaul]

We can add as many field types as we want; they're easy to create. I don't think we can guarantee API compatibility with these third-party plugins (see my original response where I marked the ones I thought would be easy for compatibility with, though I am not sure what will happen in terms of UI -- which identical field type would BP select by default?).

I'd rather have individual tickets for each field type that we think we should have.