GET errors in ruby on rails. Controllers and actions. CRUD - ruby-on-rails

Question

I'm working through the "Ruby on rails essential 3 training" on lynda.com. I'm at the point of creating forms and implementing CRUD. So far whenever I try to have rails initiate an action it can never find the definition.
To solve this problem I define the action within the controller and then create a GET within my routes.rb file. My instructor doesn't have to do this and his server starts just fine. I have a feeling I'm doing something wrong because my routes.rb file has far to many GET commands.
Please look at the following folders and let me know if you have an idea of why I have to make a GET every time I try a new action. I heard that when creating a Model there is supposed to be a GET created at the same time but that isn't happening and I'm not sure if I'm understanding that correctly. My subjects controller:
class SubjectsController < ApplicationController
def index
list
render('list')
end
# def index
# show
# render('show')
# end
def list
#subjects = Subject.order("subjects.position ASC")
end
def show
#subject = Subject.find(params[:id])
end
def new
#subject = Subject.new
end
def create
end
end
My new.html.erb file:
<%= link_to("<< Back to List", {:action => 'list'}, :class => 'back- link') %>
<div class="subject new">
<h2>Create Subject</h2>
<%= form_for(:subject, :url => {:action => 'create'}) do |f| %>
<table summary="Subject form fields">
<tr>
<th>Name</th>
<td><%= f.text_field(:name) %></td>
</tr>
<tr>
<th>Position</th>
<td><%= f.text_field(:position) %></td>
</tr>
<tr>
<th>Visible</th>
<td><%= f.text_field(:visible) %></td>
</tr>
</table>
<div class="form-buttons">
<%= submit_tag("Create Subject") %>
</div>
<% end %>
My config/routes.rb
Rails.application.routes.draw do
root :to=>"demo#index"
get 'demo/index'
get 'demo/hello'
get 'demo/other_hello'
get 'subjects/list'
get 'subjects/show'
get 'subjects/new'
get 'subjects/create'
Now having an issue with the Create portion of Crud when trying to create a test subject. Here is my SubjectsController.rb
class SubjectsController < ApplicationController
def index
list
render('list')
end
# def index
# show
# render('show')
# end
def list
#subject = Subject.order("subjects.position ASC")
end
def show
#subject = Subject.find(params[:id])
end
def new
#subject = Subject.new
end
def create
#subject = Subject.new(params[:subject])
if #subject.save
redirect_to(:action => 'list')
else
render('new')
end
end
end

Answer 1

Yes, you do not need to specify GET for CRUD actions. You can use Rails Resource Routing. For example, your subjects controller actions can be called in routes.rb like so:
resources: subjects
This will automatically route all the generic CRUD actions, and look for them in your controller. You can see whether rails "picked up" your routing by typing rake routes in the command line. You can also limit the number of actions you want by passing resources: subjects, only:[:destroy]. This tells Rails to only use the subjects#destroy action. There is more to it. I suggest reading through this RailsGuide for more information

Answer 2

Here's what your config/routes.rb should look like:
root 'subjects#index'
resources :subjects
get 'subjects/list' => 'subjects#list'

Answer 3

Normally, you have to create routes by yourself. They are not created with a model. Also, they are rather related to the controller than to the model.
I recommend to have a look at the official Rails routing guide here. Usually something like subjects/create is not a GET but a POST route. Your instructor might also have used a resources :subjects route instead of multiple GET/POST/etc. routes.

Answer 4

Slight variant of #OhHendrie's answer using only the resources dsl
root 'subjects#index'
resources :subjects do
get 'list', on: :collection
end