Not able to save from data for a nested model - ruby-on-rails

Question

I am new to rails and finishing up the Michael Hartl tutorial and creating some variations on the basic app from the book. One thing I am trying to do is create a set of model associations that is three deep (user-> colleciotn-> pictures ->). I am also trying to place my pictures form in the view for showing collections. I tried following the pattern used in the book for the User to collection relationship, but have had several issues. First, I could not use the Form_with tag (form_with(model: #picture, local: true)) and ended up writing out the path (form_with(url:"/pictures/create", method: "post")). Also, I used a hidden field tag to pass the collection_id to the "create" method.
My issue now seems to be that it is not saving the #picture data in the Picture Controller. Here is the line I think is suspect:
#picture= #collection.pictures.build
Here is a summary/my understanding of what I am trying to do.
render the Picture form on the Controller show page
Post the form date to the picture model, while also passing the
Controller object ID to the controller so to preserve the picture to controller relationship
Call the Controller object using the controller ID that was sent in
params
Save the Picture params to the Picture model with .build and flash a success message
From the logs, I believe the issue is with my use of the .build (highlighted below in code).
I will provide the code below for all of the elements of the app, as well as the log. I could really use some help figuring out what I am doing wrong. Let me know if there is anything else I should share.
Models
Picture Models
class Picture < ApplicationRecord
belongs_to :collection
validates :collection_id, presence: true
validates :picture_title, presence: true, length: { maximum: 30}
end
Collection Model
class Collection < ApplicationRecord
belongs_to :user
has_many :pictures, dependent: :destroy
default_scope -> { order(created_at: :desc) }
validates :user_id, presence: true
validates :collection_title, presence: true, length: { maximum: 30 }
end
User Model
class User < ApplicationRecord
has_many :collections, dependent: :destroy
has_many :pictures, through: :collections
attr_accessor :remember_token
before_save { self.email = email.downcase }
validates :name, presence: true, length: { maximum: 50 }
VALID_EMAIL_REGEX = /\A[\w+\-.]+#[a-z\d\-.]+\.[a-z]+\z/i
validates :email, presence: true, length: { maximum: 255 },
format: { with: VALID_EMAIL_REGEX },
uniqueness: true
has_secure_password
validates :password, presence: true, length: { minimum: 6 }, allow_nil: true
# Returns the hash digest of the given string.
def User.digest(string)
cost = ActiveModel::SecurePassword.min_cost ? BCrypt::Engine::MIN_COST :
BCrypt::Engine.cost
BCrypt::Password.create(string, cost: cost)
end
# Returns a random token.
def User.new_token
SecureRandom.urlsafe_base64
end
# Remembers a user in the database for use in persistent sessions.
def remember
self.remember_token = User.new_token
update_attribute(:remember_digest, User.digest(remember_token))
end
# Returns true if the given token matches the digest.
def authenticated?(remember_token)
return false if remember_digest.nil?
BCrypt::Password.new(remember_digest).is_password?(remember_token)
end
def forget
update_attribute(:remember_digest, nil)
end
def feed
Collection.where("user_id = ?", id)
end
end
Routes
Rails.application.routes.draw do
get 'sessions/new'
root 'static_pages#home'
get '/help', to: 'static_pages#help'
get '/about', to: 'static_pages#about'
get '/contact', to: 'static_pages#contact'
get '/signup', to: 'users#new'
get '/login', to: 'sessions#new'
post '/login', to: 'sessions#create'
delete '/logout', to: 'sessions#destroy'
post '/pictures/create', to: 'pictures#create'
resources :users
resources :collections
resources :pictures
resources :users do
resources :collection
end
resources :collections do
resources :pictures
end
end
Picure Controller
def create
#collection = Collection.find(params[:collection_id])
#picture= #collection.pictures.build
if #picture.save!
flash[:notice] = "Picture was successfully added."
redirect_to request.referrer
else
flash[:alert] = "Picture could not be saved."
redirect_to request.referrer
end
end
private
def correct_user
#collection = current_user.collections.find_by(id: params[:id])
redirect_to root_url if #collection.nil?
end
def picture_params
params.require(:picture).permit(:picture_title)
end
end
Collections Controller
class CollectionsController < ApplicationController
before_action :logged_in_user, only: [:create, :destroy, :show, :index]
before_action :correct_user, only: [:destroy, :show]
def show
#collection = Collection.find(params[:id])
#picture= Picture.new
end
def create
#collection = current_user.collections.build(collection_params)
if #collection.save
flash[:success] = "Image collection created!"
redirect_to root_url
else
#feed_items = current_user.feed.paginate(page: params[:page])
render 'static_pages/home'
end
end
def destroy
#collection.destroy
flash[:success] = "Collection deleted"
redirect_to request.referrer || root_url
end
private
def collection_params
params.require(:collection).permit(:collection_title)
end
def correct_user
#collection = current_user.collections.find_by(id: params[:id])
redirect_to root_url if #collection.nil?
end
end
**Picture Form **
<%= form_with(url:"/pictures/create", method: "post") do |f| %>
<div class="field">
<%= f.text_field :picture_title, placeholder: "Picture Title" %>
</div>
<%= f.submit "Create Collection", class: "btn btn-primary" %>
<%= hidden_field_tag :collection_id, #collection.id %>
<% end %>
Logs
Started POST "/pictures/create" for 99.150.231.55 at 2020-01-04 19:29:08 +0000
Cannot render console from 99.150.231.55! Allowed networks: 127.0.0.0/127.255.255.255, ::1
Processing by PicturesController#create as JS
Parameters: {"authenticity_token"=>"GNDEKiGPVP7EHRtgphGDMIJxbKgnXn2MFSmgTJMIoEo2Owan5THjMIx9N8pKLkS7hmaqJMdwhjqvuOBR/3JaHg==", "picture_title"=>"TEST", "collection_id"=>"10", "commit"=>"Create Collection"}
User Load (0.1ms) SELECT "users".* FROM "users" WHERE "users"."id" = ? LIMIT ? [["id", 1], ["LIMIT", 1]]
↳ app/helpers/sessions_helper.rb:18:in `current_user'
Collection Load (0.1ms) SELECT "collections".* FROM "collections" WHERE "collections"."id" = ? ORDER BY "collections"."created_at" DESC LIMIT ? [["id", 10], ["LIMIT", 1]]
↳ app/controllers/pictures_controller.rb:12:in `create'
Completed 500 Internal Server Error in 6ms (ActiveRecord: 0.2ms | Allocations: 2423)
NoMethodError (undefined method `picture_title=' for nil:NilClass):
app/controllers/pictures_controller.rb:14:in `create'
EDIT
I implemented Max's code corrections, but now getitng the following error:
Started POST "/collections/10/pictures" for 99.150.231.55 at 2020-01-05 17:57:57 +0000
Cannot render console from 99.150.231.55! Allowed networks: 127.0.0.0/127.255.255.255, ::1
(0.1ms) SELECT sqlite_version(*)
NoMethodError (undefined method `make_response!' for PicturesController:Class):

Answer 1

A lot of things are off here. First axe this junk:
post '/pictures/create', to: 'pictures#create' # never do this again please.
The route here to create a picture is going to be POST /collections/:collection_id/pictures. Which RESTfully describes that we are creating a picture that belongs to a collection. You already have that route setup by:
resources :collections do
resources :pictures
end
In rails the action is only ever in the path for /edit and /new. All the other actions are defined by the HTTP verb.
class PicturesController < ApplicationController
before_action :set_collection, only: [:new, :create, :index]
# POST /collections/1/pictures
def create
#picture = #collection.pictures.new(picture_params)
if #picture.save
flash[:notice] = "Picture was successfully added."
redirect_to #collection
else
flash.now[:alert] = "Picture could not be saved."
render 'collections/show'
end
end
# ...
private
def set_collection
#collection = Collection.find(params[:collection_id])
end
def picture_params
params.require(:picture).permit(:picture_title)
end
end
Don't do redirect_to request.referrer when a record is not valid (or really at all). Many clients do not send the HTTP referer header and it will make for a really bad user experience as any user input and the validation messages are lost. Most of the time you actually know where you should send the user like in your Collections#destroy method which should probably redirect to the index or the users feed. If you really want redirect back reliably save the location in the session.
The form should read:
<%= form_with(model: [#collection, #picture]) do |f| %>
<div class="field">
<%= f.text_field :picture_title, placeholder: "Picture Title" %>
</div>
<%= f.submit %>
<% end %>
Since the collection id is in the path we don't need to do that hacky garbage of using a hidden input to pass it. This also binds the form to the model instance so that the user input is not lost if the input is invalid.