undefined method `update' for nil:NilClass. Friendly_id and Scaffolded controller - ruby-on-rails

Question

I am getting this error saying undefined method update. The show and Edit buttons work well. It's just the update that isn't working. I am using friendly_id and the controller is scaffolded with better routing.
Here is my routes:
Rails.application.routes.draw do
resources :static_pages, except: [:show, :edit]
devise_for :users
mount Bootsy::Engine => '/bootsy', as: 'bootsy'
get 'profile' => "users#profile"
root 'indexes#index'
get ':slug', to: 'static_pages#show'
get ':slug/edit', to: 'static_pages#edit'
# The priority is based upon order of creation: first created -> highest priority.
# See how all your routes lay out with "rake routes".
# You can have the root of your site routed with "root"
# root 'welcome#index'
# Example of regular route:
# get 'products/:id' => 'catalog#view'
# Example of named route that can be invoked with purchase_url(id: product.id)
# get 'products/:id/purchase' => 'catalog#purchase', as: :purchase
# Example resource route (maps HTTP verbs to controller actions automatically):
# resources :products
# Example resource route with options:
# resources :products do
# member do
# get 'short'
# post 'toggle'
# end
#
# collection do
# get 'sold'
# end
# end
# Example resource route with sub-resources:
# resources :products do
# resources :comments, :sales
# resource :seller
# end
# Example resource route with more complex sub-resources:
# resources :products do
# resources :comments
# resources :sales do
# get 'recent', on: :collection
# end
# end
# Example resource route with concerns:
# concern :toggleable do
# post 'toggle'
# end
# resources :posts, concerns: :toggleable
# resources :photos, concerns: :toggleable
# Example resource route within a namespace:
# namespace :admin do
# # Directs /admin/products/* to Admin::ProductsController
# # (app/controllers/admin/products_controller.rb)
# resources :products
# end
end
Here is the static page controller for the update method:
class StaticPagesController < ApplicationController
before_action :set_static_page, only: [:show, :edit, :update]
before_action :static_page_params, only: [:update, :create]
before_action :destroy_static_page, only: :destroy
before_filter :except => [:show] do
redirect_to :new_user_session unless current_user && current_user.role == 5
end
# GET /static_pages
# GET /static_pages.json
def index
#static_pages = StaticPage.all
end
# GET /static_pages/1
# GET /static_pages/1.json
def show
end
# GET /static_pages/new
def new
#static_page = StaticPage.new
end
# GET /static_pages/1/edit
def edit
end
# POST /static_pages
# POST /static_pages.json
def create
#static_page = StaticPage.new(static_page_params)
respond_to do |format|
if #static_page.save
format.html { redirect_to #static_page, notice: 'Static page was successfully created.' }
format.json { render :show, status: :created, location: #static_page }
else
format.html { render :new }
format.json { render json: #static_page.errors, status: :unprocessable_entity }
end
end
end
# PATCH/PUT /static_pages/1
# PATCH/PUT /static_pages/1.json
def update
respond_to do |format|
if #static_page.update(static_page_params)
format.html { redirect_to #static_page, notice: 'Static page was successfully updated.' }
format.json { render :show, status: :ok, location: #static_page }
else
format.html { render :edit }
format.json { render json: #static_page.errors, status: :unprocessable_entity }
end
end
end
# DELETE /static_pages/1
# DELETE /static_pages/1.json
def destroy
#static_page.destroy
respond_to do |format|
format.html { redirect_to static_pages_url, notice: 'Static page was successfully destroyed.' }
format.json { head :no_content }
end
end
private
# Use callbacks to share common setup or constraints between actions.
def set_static_page
#static_page = StaticPage.find_by_slug(params[:slug])
end
def destroy_static_page
#static_page = StaticPage.find_by_slug(params[:slug])
end
# Never trust parameters from the scary internet, only allow the white list through.
def static_page_params
params.require(:static_page).permit(:title, :video_id, :content, :tags, :author, :date, :slug)
end
end
Here are the views that have been scaffolded for the edit page:
%h1 Editing static_page
= render 'form'
= link_to 'Show', #static_page
\|
= link_to 'Back', static_pages_path
Edit: It has to do with my routes. I can't get the show button to work on the fourm bellow. I try #static_page.slug but that takes me to /page_name/page_name. When I just do #static_page it takes me to /static_page/page_name. What I need it to do is take me to /page_name.
Edit 2: Here is the form partial:
= simple_form_for(#static_page) do |f|
= f.error_notification
.form-inputs
= f.input :title
= f.input :video_id
.bootsy_text_area
= f.bootsy_area :content, :class => 'form-control', rows: 12
= f.input :tags
= f.input :author
= f.input :date
.form-actions
= f.button :submit

Answer 1

You're calling #static_page.update(static_page_params), but in this case, #static_page is nil.
You've defined #static_page as #static_page = StaticPage.find_by_slug(params[:slug]), but this will return nil if no page with that slug is found.
There are two ways you can handle this:
Use find_by_slug! instead, which will raise an exception if no record is found, or:
Check for the presence of nil yourself, and decide how you want to handle it.