add dropdowns for client, owner, builder in subproject form

app/helpers/subprojects_helper.rb

@@ -1,6 +1,6 @@
 module SubprojectsHelper
   def subproject_form_fields
-    [:subproject_name, :project_id, :client_id, :owner_id, :builder_id]
+    [:subproject_name, :project, :client, :owner, :builder]
   end
 
   def subproject_view_fields

app/views/subprojects/_form.html.erb

@@ -14,7 +14,14 @@
   <% subproject_form_fields.each do |attrib| %>
   <div>
     <%= form.label attrib, style: "display: block" %>
-    <%= form.text_field attrib, value: subproject.send(attrib) %>
+    <% case attrib %>
+      <% when :project %>
+        <%= form.collection_select :project_id, Project.all, :id, -> (project) { "#{project.name}" }, prompt: "Select Project" %>
+      <% when :client, :owner, :builder %>
+        <%= form.collection_select "#{attrib}_id", Client.all, :id, -> (client) { "#{client.company_name} (#{client.lastname}, #{client.firstname})" }, prompt: "Select #{attrib.capitalize}" %>
+    <% else %>
+      <%= form.text_field attrib, value: subproject.send(attrib) %>
+    <% end %>
   </div>
   <% end %>