editing namespaced resource - ruby-on-rails

Question

I'm trying to hook up a link that will take users from a lesson show page (that lists a bunch of words) to a form to edit one of the listed words. I have a teacher namespace, such that teachers have many lessons and lessons have many words. Before working on a form to edit the word, the lesson show page is breaking when I add the link to what would be the edit form: ActionController::UrlGenerationError in Teacher::Lessons#show, No route matches {:action=>"edit", :controller=>"teacher/words", :id=>nil, :lesson_id=>#<Word id: 19, term: "la casa", reference: "house", lesson_id: 6, created_at: "2016-06-05 23:19:19", updated_at: "2016-06-05 23:19:19", image: "house.jpeg", sound: "test.mp3">} missing required keys: [:id]
What am I missing in regards to setting the edit_teacher_lesson_word link?
Rails.application.routes.draw do
devise_for :users
root 'static_pages#index'
resources :lessons, only: [:index, :show]
resources :words, only: [:show]
namespace :teacher do
resources :lessons, only: [:show, :new, :edit, :create, :update] do
resources :words, only: [:new, :edit, :create, :update]
end
end
end
teacher/words_controller:
class Teacher::WordsController < ApplicationController
before_action :authenticate_user!
before_action :require_authorized_for_current_lesson
def new
#word = Word.new
end
def edit
#word = Word.find(params[:id])
end
def create
#word = current_lesson.words.create(word_params)
if #word.valid?
redirect_to teacher_lesson_path(current_lesson)
else
render :new, status: :unprocessable_entity
end
end
private
def require_authorized_for_current_lesson
if current_lesson.user != current_user
render text: 'Unauthorized', status: :unauthorized
end
end
helper_method :current_lesson
def current_lesson
#current_lesson ||= Lesson.find(params[:lesson_id])
end
def word_params
params.require(:word).permit(:term, :reference, :image, :sound)
end
end
teacher/lessons_controller:
class Teacher::LessonsController < ApplicationController
before_action :authenticate_user!
before_action :require_authorized_for_current_lesson, only: [:show, :edit, :update]
def show
#lesson = Lesson.find(params[:id])
end
def new
#lesson = Lesson.new
end
def edit
#lesson = Lesson.find(params[:id])
end
def create
#lesson = current_user.lessons.create(lesson_params)
if #lesson.valid?
redirect_to teacher_lesson_path(#lesson)
else
render :new, status: :unprocessable_entity
end
end
def update
current_lesson.update_attributes(lesson_params)
redirect_to teacher_lesson_path(current_lesson)
end
private
def require_authorized_for_current_lesson
if current_lesson.user != current_user
render text: "Unauthorized", status: :unauthorized
end
end
def current_lesson
#current_lesson ||= Lesson.find(params[:id])
end
def lesson_params
params.require(:lesson).permit(:title, :description, :subject, :difficulty)
end
end
teacher/lessons/show:
<div class ="booyah-box col-xs-10 col-xs-offset-1">
<br>
<p class="text-center"><%= #lesson.description %></p>
<br>
<div class="text-center">
<%= link_to 'Edit Lesson', edit_teacher_lesson_path(#lesson), class: 'btn btn-primary' %>
<%= link_to 'Student View', lesson_path(#lesson), class: 'btn btn-warning' %>
<%= link_to 'My Lessons', '#', class: 'btn btn-success' %>
<%= link_to 'All Lessons', lessons_path, class: 'btn btn-info' %>
</div>
<hr>
<h3>Vocabulary in This Lesson</h3>
<%= link_to 'Add word', new_teacher_lesson_word_path(#lesson), class: 'btn btn-primary btn-lg pull-right' %>
<ul>
<% #lesson.words.each do |word| %>
<li>
<b><%= word.term %></b> means <i><%= word.reference %></i>
<%= link_to 'Edit', edit_teacher_lesson_word_path(word), class: 'btn btn-primary' %>
</li>
<% end %>
</ul>
</div>
rake routes:
new_user_session GET /users/sign_in(.:format) devise/sessions#new
user_session POST /users/sign_in(.:format) devise/sessions#create
destroy_user_session DELETE /users/sign_out(.:format) devise/sessions#destroy
user_password POST /users/password(.:format) devise/passwords#create
new_user_password GET /users/password/new(.:format) devise/passwords#new
edit_user_password GET /users/password/edit(.:format) devise/passwords#edit
PATCH /users/password(.:format) devise/passwords#update
PUT /users/password(.:format) devise/passwords#update
cancel_user_registration GET /users/cancel(.:format) devise/registrations#cancel
user_registration POST /users(.:format) devise/registrations#create
new_user_registration GET /users/sign_up(.:format) devise/registrations#new
edit_user_registration GET /users/edit(.:format) devise/registrations#edit
PATCH /users(.:format) devise/registrations#update
PUT /users(.:format) devise/registrations#update
DELETE /users(.:format) devise/registrations#destroy
root GET / static_pages#index
lessons GET /lessons(.:format) lessons#index
lesson GET /lessons/:id(.:format) lessons#show
word GET /words/:id(.:format) words#show
teacher_lesson_words POST /teacher/lessons/:lesson_id/words(.:format) teacher/words#create
new_teacher_lesson_word GET /teacher/lessons/:lesson_id/words/new(.:format) teacher/words#new
edit_teacher_lesson_word GET /teacher/lessons/:lesson_id/words/:id/edit(.:format) teacher/words#edit
teacher_lesson_word PATCH /teacher/lessons/:lesson_id/words/:id(.:format) teacher/words#update
PUT /teacher/lessons/:lesson_id/words/:id(.:format) teacher/words#update
teacher_lessons POST /teacher/lessons(.:format) teacher/lessons#create
new_teacher_lesson GET /teacher/lessons/new(.:format) teacher/lessons#new
edit_teacher_lesson GET /teacher/lessons/:id/edit(.:format) teacher/lessons#edit
teacher_lesson GET /teacher/lessons/:id(.:format) teacher/lessons#show
PATCH /teacher/lessons/:id(.:format) teacher/lessons#update
PUT /teacher/lessons/:id(.:format) teacher/lessons#update

Answer 1

looks like you're passing a Word where it's expecting a Lesson. see this part of the error message: :lesson_id=>#<Word id: 19,
I'm guessing, but probably this is the wrong line of code:
edit_teacher_lesson_word_path(word)
your route file says this about that route:
edit_teacher_lesson_word GET /teacher/lessons/:lesson_id/words/:id/edit(.:format)
the : indicates what things you need to pass in order to create a valid route... and here you need both :lesson_id as well as :id and you are only passing one of those (and it's getting confused about which one).
Usually you'd instantiate this route with both lesson and word eg:
edit_teacher_lesson_word_path(#lesson, word)
Try that (or variations on it) to get it to work.