Pass other field data into custom field types

[edalzell]

Use case

I now have settings for my addons:

In this case, I'd love to be able to make select drop downs for the Tag and the Consent field. In the former, I'd need access to the Audience data and the latter I need access to the Form data.

Would be amazing if a field type had access to the other fields in the blueprint, like the "context".

Bonus points if we could "link" them so that when one was updated, we could update ours. Like if someone picked a new form, I could update the Consent Field options.

[edalzell]

Thinking about this more I believe it can be done w/ a few changes/enhancements:

• Fieldtypes emit a "changed" event that includes the new value and the handle of the field that changed
• Fieldtypes add a config that indicates which "handle" events to listen to (i.e. subscribe_to: field_handle)
• The generic types (relationship, etc), listen for all events and if matching the subscribe_to, call function to retrieve the new data (give that function a standard name the custom field types can implement). This function gets passed the value of "subscribed" field.

[edalzell]

Even more thinking...this could use the $events bus.