Add references between projects and todos

app/controllers/todos_controller.rb

@@ -65,6 +65,6 @@ class TodosController < ApplicationController
 
     # Only allow a list of trusted parameters through.
     def todo_params
-      params.expect(todo: [ :name, :description ])
+      params.expect(todo: [ :name, :description, :completed, :priority, :project_id ])
     end
 end

app/models/project.rb

@@ -1,3 +1,4 @@
 class Project < ApplicationRecord
+  has_many :todos, dependent: :destroy
   validates :name, presence: true
 end

app/models/todo.rb

@@ -1,2 +1,3 @@
 class Todo < ApplicationRecord
+  belongs_to :project
 end

app/views/projects/show.html.erb

@@ -1,4 +1,9 @@
 <h1><%= @project.name %></h1>
+
+<% @project.todos.each do |todo| %>
+  <li><%= link_to todo.name, todo_path(todo) %></li>
+<% end %>
+
 <%= link_to "Edit", edit_project_path %>
 <%= button_to "Delete", project_path, method: :delete %>
 <%= link_to "Back", projects_path %>

app/views/todos/_form.html.erb

@@ -21,6 +21,21 @@
     <%= form.textarea :description %>
   </div>
 
+  <div>
+    <%= form.label :completed %>
+    <%= form.check_box :completed %>
+  </div>
+
+  <div>
+    <%= form.label :priority %>
+    <%= form.number_field :priority %>
+  </div>
+
+  <div>
+    <%= form.label :project_id %>
+    <%= form.collection_select :project_id, Project.all, :id, :name, prompt: "Select a project" %>
+  </div>
+
   <div>
     <%= form.submit %>
   </div>

app/views/todos/_todo.html.erb

@@ -9,4 +9,18 @@
     <%= todo.description %>
   </div>
 
+  <div>
+    <strong>Completed:</strong>
+    <%= todo.completed %>
+  </div>
+
+  <div>
+    <strong>Priority:</strong>
+    <%= todo.priority %>
+  </div>
+
+  <div>
+    <strong>Project:</strong>
+    <%= link_to todo.project.name, project_path(todo.project) %>
+  </div>
 </div>

db/migrate/20251027123148_add_project_id_to_todos.rb

@@ -0,0 +1,5 @@
+class AddProjectIdToTodos < ActiveRecord::Migration[8.1]
+  def change
+    add_reference :todos, :project, null: false, foreign_key: true
+  end
+end

db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[8.1].define(version: 2025_10_27_122702) do
+ActiveRecord::Schema[8.1].define(version: 2025_10_27_123148) do
   create_table "projects", force: :cascade do |t|
     t.boolean "active", default: true, null: false
     t.datetime "created_at", null: false
@@ -24,6 +24,10 @@ ActiveRecord::Schema[8.1].define(version: 2025_10_27_122702) do
     t.text "description"
     t.string "name"
     t.integer "priority", default: 1, null: false
+    t.integer "project_id", null: false
     t.datetime "updated_at", null: false
+    t.index ["project_id"], name: "index_todos_on_project_id"
   end
+
+  add_foreign_key "todos", "projects"
 end