check if clients are editable

app/models/client.rb

@@ -5,4 +5,12 @@ class Client < ApplicationRecord
 
   validates :company_name, :firstname, :lastname, presence: true
   # Add other validations as needed
+
+  def referenced_count
+    owner_subprojects.count + builder_subprojects.count + client_subprojects.count
+  end
+
+  def editable?
+    referenced_count <= 1
+  end
 end

app/views/clients/_form.html.erb

@@ -1,3 +1,4 @@
+<% if @client.editable? %>
   <%= form_with(model: client) do |form| %>
     <% if client.errors.any? %>
       <div style="color: red">
@@ -11,52 +12,17 @@
       </div>
     <% end %>
 
+    <% [:company_name, :firstname, :lastname, :streetname, :zipcode, :city, :country, :email, :phone].each do |attrib|%>
       <div>
-    <%= form.label :company_name, style: "display: block" %>
-    <%= form.text_field :company_name %>
-  </div>
-
-  <div>
-    <%= form.label :firstname, style: "display: block" %>
-    <%= form.text_field :firstname %>
-  </div>
-
-  <div>
-    <%= form.label :lastname, style: "display: block" %>
-    <%= form.text_field :lastname %>
-  </div>
-
-  <div>
-    <%= form.label :streetname, style: "display: block" %>
-    <%= form.text_field :streetname %>
-  </div>
-
-  <div>
-    <%= form.label :zipcode, style: "display: block" %>
-    <%= form.text_field :zipcode %>
-  </div>
-
-  <div>
-    <%= form.label :city, style: "display: block" %>
-    <%= form.text_field :city %>
-  </div>
-
-  <div>
-    <%= form.label :country, style: "display: block" %>
-    <%= form.text_field :country %>
-  </div>
-
-  <div>
-    <%= form.label :email, style: "display: block" %>
-    <%= form.text_field :email %>
-  </div>
-
-  <div>
-    <%= form.label :phone, style: "display: block" %>
-    <%= form.text_field :phone %>
+        <%= form.label attrib, style: "display: block" %>
+        <%= form.text_field attrib %><br>
       </div>
+    <% end %>
 
     <div>
       <%= form.submit %>
     </div>
   <% end %>
+<% else %>
+  <p>This client is used in multiple subprojects and cannot be edited.</p>
+<% end %>