add api end point to show custom fields exposed in the API

app/controllers/api/v1/custom_fields_controller.rb

@@ -0,0 +1,39 @@
+class API::V1::CustomFieldsController < ApplicationController
+    skip_before_action :authenticate_user!
+
+    def index
+      render json: json_tree(CustomFieldSection.api_public.includes(:custom_fields)).to_json
+    end
+
+    private
+
+    def json_tree(custom_field_sections)
+      custom_field_sections.map do |section|
+        {
+          id: section.id,
+          name: section.name,
+          hint: section.hint,
+          custom_fields: section.custom_fields.map do |field|
+            field_hash = {
+                id: field.id,
+                current_reference: "#{section.name.parameterize}--#{field.key.parameterize}",
+                key: field.key,
+                hint: field.hint,
+                field_type: field.field_type
+              }
+              field_hash[:options] = process_options(field.options) if field.field_type == 'select'
+              field_hash
+          end
+        }
+      end
+    end
+
+    def process_options(options_string)
+        options_string.split(',').map.with_index(1) do |option, index|
+          {
+            value: option.strip,
+            # key: option.strip.parameterize
+          }
+        end
+      end
+  end

app/models/custom_field_section.rb

@@ -7,4 +7,6 @@ class CustomFieldSection < ApplicationRecord
     default_scope { order(sort_order: :asc) }
 
     scope :visible_to, -> (current_user){ current_user.admin ? all : where(public: true) }
+
+    scope :api_public, -> { where(api_public: true) }
 end

app/views/admin/custom_field_sections/_repeatable-fields.html.erb

@@ -20,6 +20,10 @@
     <%= c.text_area :hint, class: "field__input", rows: 1 %>
 </div>
 
+<% if c.object.custom_field_section&.api_public %>
+<p>Current reference key: <em><%= c.object.custom_field_section&.name&.parameterize %>--<%= c.object.key&.parameterize %></em></p>
+<% end %>
+
 <%= c.hidden_field :_destroy,  data: {destroy_field: true} %>
 
 <button type="button" class="repeater__closer" data-close="true" title="Remove this field">Remove this field</button>

config/routes.rb

@@ -82,6 +82,7 @@
       resources :accessibilities, only: [:index]
       get "me", to: "me#show"
       resources :services, only: [:index, :show]
+      resources :custom_fields, only: [:index]
     end
   end