Difficulty adding custom form action

[ryanb]

I'm attempting to add an extend_trial action to AccountsController. I added a route:

resources :accounts do
  member do
    get :extend_trial
  end
end

And the controller action which has the same behavior as the edit action:

def extend_trial
  edit
end

And then I copied the edit view to extend_trial.html.erb with one field:

<%
# decorate first on every page or partial
decorated = decorate resource
%>
<article class="resource">
  <div class="resource__header">
    <h1><%= t 'labels.edit', id: decorated.id %></h1>
    <%= render 'resource_navs' %>
  </div>
  <%= render 'flash_messages' %>
  <section>
    <div class="resource__container">
      <%= form_for decorated, url: url_for(action: :show), method: :put, html: { multipart: true }, builder: Wallaby::FormBuilder do |form| %>
        <% decorated.errors[:base].try do |messages| %>
          <% Array(messages).each do |message| %>
            <div class="alert alert-danger alert-dismissible" role="alert">
              <%= raw message %>
            </div>
          <% end %>
        <% end %>
        <%= type_render decorated.form_type_of("trial_end_date"), field_name: "trial_end_date", form: form %>
        <%= form.button t('buttons.save'), class: 'btn btn-primary' %>
        <%= cancel_link html_options: { class: 'btn btn-default' } %>
      <% end %>
    </div>
  </section>
</article>

This produced the following error:

undefined method `extend_trial_metadata_of' for #<SupportAdmin::AccountDecorator:0x00007ff815720078>

It took some digging to realize there's a form_metadata_of method which I assume is the behavior I want so I aliased it:

# in AccountDecorator
alias_method :extend_trial_metadata_of, :form_metadata_of

Then I get this error:

ActionView::MissingTemplate - Missing partial /extend_trial/_datetime, /_datetime, support_admin/accounts/extend_trial/_datetime, support_admin/accounts/_datetime, support_admin/application/extend_trial/_datetime, support_admin/application/_datetime, wallaby/resources/extend_trial/_datetime, wallaby/resources/_datetime with {:locale=>[:"en-US"], :formats=>[:html], :variants=>[], :handlers=>[:raw, :erb, :html, :builder, :ruby, :jbuilder]}. Searched in:
  * "/Users/rbates/code/envisage/app/views"
  * "/Users/rbates/.rbenv/versions/2.5.5/lib/ruby/gems/2.5.0/gems/kaminari-core-1.1.1/app/views"
  * "/Users/rbates/.rbenv/versions/2.5.5/lib/ruby/gems/2.5.0/gems/ckeditor-4.2.4/app/views"
  * "/Users/rbates/.rbenv/versions/2.5.5/lib/ruby/gems/2.5.0/gems/wallaby-6.1.0/app/views"
  * "/Users/rbates/.rbenv/versions/2.5.5/lib/ruby/gems/2.5.0/gems/devise_invitable-1.7.4/app/views"
  * "/Users/rbates/.rbenv/versions/2.5.5/lib/ruby/gems/2.5.0/gems/devise-4.5.0/app/views"

So I add a partial at accounts/_datetime.html.erb which delegates to the internal date time partial:

<%= render partial: "wallaby/resources/form/datetime", locals: local_assigns %>

The form now renders (yay) but doesn't look quite right since the body tag doesn't have an edit class due to a different action name. This would be resolved by not nesting CSS as mentioned in #174.

When I submit the form I get this error:

NameError - undefined local variable or method `form' for #<#<Class:0x00007fc934466f18>:0x00007fc93bfdb068>
Did you mean?  fork:
  app/views/support_admin/accounts/_datetime.html.erb:1:in `_app_views_support_admin_accounts__datetime_html_erb__554914958012286755_70251162594040'

The logs show the update action worked and redirected to the show action which resulted in this error. It appears the custom datetime partial I added is being used by the show action but does not have a form variable. It is confusing to have two partials with the same name that have different behavior and locals. I suggest renaming the the form partials to datetime_field and moving them out of the form directory. Flat lists with unique names are good for customizability.

I moved the partial to accounts/extend_trial/datetime which resolves the error and renders the page.

Overall this was quite difficult to figure out. I suggest smoothing out this process and adding some documentation for customizing Wallaby in this way.