bug fixing using cursor

app/controllers/clients_controller.rb

@@ -49,8 +49,15 @@ class ClientsController < ApplicationController
 
   # DELETE /clients/1 or /clients/1.json
   def destroy
-    @client.destroy!
+    if @client.referenced_count > 0
+      respond_to do |format|
+        format.html { redirect_to clients_path, alert: "Client is referenced by subprojects and cannot be deleted." }
+        format.json { render json: { error: "Client has references" }, status: :unprocessable_entity }
+      end
+      return
+    end
 
+    @client.destroy!
     respond_to do |format|
       format.html { redirect_to clients_path, status: :see_other, notice: "Client was successfully destroyed." }
       format.json { head :no_content }

app/helpers/subprojects_helper.rb

@@ -10,9 +10,9 @@ module SubprojectsHelper
   def subproject_form_input(form, attrib, subproject)
     case attrib
     when :project
-      form.collection_select :project_id, Project.all, :id, ->(project) { project.name }, prompt: "Select Project"
+      form.collection_select :project_id, Project.all, :id, :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.to_s.capitalize}"
+      form.collection_select "#{attrib}_id", Client.all, :id, :display_name, prompt: "Select #{attrib.to_s.capitalize}"
     else
       form.text_field attrib, value: subproject.send(attrib)
     end

app/models/client.rb

@@ -13,4 +13,8 @@ class Client < ApplicationRecord
   def editable?
     referenced_count <= 1
   end
+
+  def display_name
+    "#{company_name} (#{lastname}, #{firstname})"
+  end
 end

app/models/project.rb

@@ -1,5 +1,5 @@
 class Project < ApplicationRecord
-  has_many :subprojects, inverse_of: :project
+  has_many :subprojects, inverse_of: :project, dependent: :destroy
   accepts_nested_attributes_for :subprojects, allow_destroy: true, reject_if: :all_blank
 
   validates :name, presence: true

app/views/projects/_form.html.erb

@@ -56,8 +56,6 @@
     </div>
   <% end %>
 
-</div>
-
   <div>
     <%= form.submit %>
   </div>