Why is post/create method failing with error - ruby-on-rails

Question

I'm new to RoR. Wanted to try if my next web app should be RoR based. Started out following this trail: https://guides.rubyonrails.org/getting_started.html. Worked like a charm in the beginning, but i'm unable to get the darn thing to create new records. Any hint as to what i'm missing is appreciated.
The error i'm getting is this:
D, [2020-12-18T09:59:56.917197 #132399] DEBUG -- : Createevent
F, [2020-12-18T09:59:56.917893 #132399] FATAL -- :
ActionController::ParameterMissing (param is missing or the value is empty: Event):
app/controllers/event_controller.rb:33:in `event_params'
My routing looks like this:
Rails.application.routes.draw do
post 'event/new', to: 'event#create'
resources :event
end
(I'm baffled by the need for specifying the POST above, but without it the create is never fired. ).
The eventcontroller looks like this:
class EventController < ApplicationController
def index
#events = Event.all
end
def show
#event = Event.find(params[:id])
end
def new
logger = Rails.logger
logger.info 'NewEvent'
#event = Event.new
end
def create
logger = Rails.logger
logger.debug 'Createevent'
#event = Event.new(event_params)
logger.debug 'Eventcreated'
if #event.save
redirect_to event_path
else
render :new
end
end
private
def event_params
params.require(:Event).permit(:EventName, :Description, :EventStart, :EventEnd, :Maxparticipants, :Waitlist )
end
end
Index and show works fine.
The new.html.erb looks like this:
<h1>New Event</h1>
dsfsdfds
<%= form_with model: #Event do |form| %>
<div>
<%= form.label :eventname %><br>
<%= form.text_field :EventName %>
<%= #event.errors.full_messages_for(:EventName).each do |message| %>
<div><%= message %></div>
<% end %>
</div>
<div>
<%= form.label :Description %><br>
<%= form.text_field :Description %>
<%= #event.errors.full_messages_for(:description).each do |message| %>
<div><%= message %></div>
<% end %>
</div>
<div>
<%= form.label :EventStart %><br>
<%= form.text_field :EventStart %>
<%= #event.errors.full_messages_for(:eventstart).each do |message| %>
<div><%= message %></div>
<% end %>
</div>
<div>
<%= form.label :Eventend %><br>
<%= form.text_field :Eventend %>
<%= #event.errors.full_messages_for(:eventend).each do |message| %>
<div><%= message %></div>
<% end %>
</div>
<div>
<%= form.label :Maxparticipants %><br>
<%= form.text_field :Maxparticipants %>
<%= #event.errors.full_messages_for(:Maxparticipants).each do |message| %>
<div><%= message %></div>
<% end %>
</div>
<div>
<%= form.label :Waitlist %><br>
<%= form.text_field :Waitlist %>
<%= #event.errors.full_messages_for(:waitlist).each do |message| %>
<div><%= message %></div>
<% end %>
</div>
<div>
<%= form.submit %>
</div>
<%= submit_tag "Create" %>
<% end %>
Routes:
Prefix Verb URI Pattern Controller#Action
event_new POST /event/new(.:format) event#create
event_index GET /event(.:format) event#index
POST /event(.:format) event#create
new_event GET /event/new(.:format) event#new
edit_event GET /event/:id/edit(.:format) event#edit
event GET /event/:id(.:format) event#show
PATCH /event/:id(.:format) event#update
PUT /event/:id(.:format) event#update
DELETE /event/:id(.:format) event#destroy
Things created using:
bin/rails generate model Event EventName:string Description:string EventStart:datetime EventEnd:datetime Maxparticipants:integer WaitList:integer
bin/rails generate controller Event index
Version:
About your application's environment
Rails version 6.0.3.4
Ruby version ruby 2.7.2p137 (2020-10-01 revision 5445e04352) [x86_64-linux]
RubyGems version 3.1.4
Rack version 2.2.3
Thanks to Hackman & nathanvda for clarifying. I scratched everything and started over and i finally got it working. Still way too much woodo and black magic for my taste though. The error message part got me baffled for three consecutive hours.
As stated i followed the guide and therefore ended up using (in new)
<%= form_with model: #event do |form| %>
<% if #event.errors.any? %>
<h2>Errors</h2>
<ul>
<% #event.errors.full_messages.each do |message| %>
<li><%= message %></li>
<% end %>
</ul>
<% end %>
...
Which works (well, sort of). The record gets saved if ok, the validations rules gets fired
class Event < ApplicationRecord
validates :eventname, presence: true
validates :description, presence: true, length: { minimum: 20 }
end
and if violated no record gets written to the database, but no error messages either. Nil. Nothing. After poking around on the internet i ended up changing to
<%= form_for #event do |form| %>
and then error reporting works. Only problem with this solution is that the use of form_for is discouraged as it is being rendered obsolete.
Final version ended up being:
<%= form_with model: #event, local: true do |form| %>
Which does the trick.
Next step in my evaluation will be the use of natural keys as the use of surrogate keys is not an option for some of the data structures needed in this project. (during my poking around i got the impression that natural keys are some kind of a sore tooth in RoR, but time will show.

Answer 1

To start out, your resources in the routes should be pluralized. So resources :event should be resources :events
Also the controller name should be pluralized. So EventController would become EventsController.
Now the needed routes should work fine and you can get rid of the specified POST in your routes.rb
Now inside your controller you have the event_params method. There it is preferred to downcase/snake_case the names like this:
def event_params
params.require(:event).permit(:event_name #etc)
end
If your column names in DB are EventName etc, I would advice to rename them.
Last thing: In your form you got #Event with uppercase while in the controller#new action you defined #event with lowercase. Use lowercase everywhere.

Answer 2

So if you had started as follows:
bin/rails generate model Event event_name:string description:string event\-start:datetime event_end:datetime max_participants:integer wait_list:integer
bin/rails generate controller events index
Then the generated code would work a lot better.
A few tips to clarify:
in ruby we only write classes with a capital, for variables we use snake case (everything lowercase and words connected with underscores). So by extension when generating a model all attributes should be snake cased
a controller in general uses the plural form, since it "controls" all the events (not just one).