Convert active_admin_form_for to Arbre component - resolves #2542

[varyonic]

Resolves #2542. Uses FormBuilderProxy as suggested by Igor in #2689, removing and replacing form_buffers from ActiveAdmin::FormBuilder. As a bonus allows 'inputs', etc. instead of 'f.inputs' in DSL. Allowing Arbre within has_many block deferred as a second step. May break existing code that mixes ERB inside active_admin_form_for in a template. Can also break other code that makes assumptions about the context of the block, see fix to active_admin_comments.rb included.

[timoschilling]

Can you add some examples into the readme and/or the docs

[zorab47]

Wow, awesome work. 😸

[timoschilling]

Is the old way still supported?

[timoschilling]

An the fist look it's great! 👍

Please apply my notes and make repush, to get more overview

[timoschilling]

I'm not sure, but c10a6c4 can bring problems to the developer.
@seanlinsley what is your opinion to c10a6c4?

[timoschilling]

I think many users use f.form_buffers in there code. @varyonic and @seanlinsley how should we deal with that?

def form_buffers
  raise "`form_buffers` has removed from ActiveAdmin:: FormBuilder, please read https://github.com/activeadmin/activeadmin/blob/master/docs/5-forms.md for details."
end

[Fivell]

Agree about f.form_buffers , we have too many projects using AA from edge, this change is critical for us ...

[varyonic]

@timoschilling I added a backwardly compatible form_buffers method with a deprecation warning.

[seanlinsley]

I'd rather just raise an error. The next release is going to be 1.0.0, and we'll be following semantic versioning. I really don't want that cruft in the code base until 2.0.0

[timoschilling]

@varyonic nice work, but I have the same meaning as @seanlinsley

[varyonic]

Moved backwardly compatible version of form_buffers to https://gist.github.com/varyonic/542c37648de91a02402a If anyone decides to use it please star and comment on the gist.

[timoschilling]

@varyonic thanks for your great work on this!!! 👍 ❤️