如何在Rails 5中提出两个模型的一对多关系视图

Question

I'm trying to set up a one to many relationship between one model to another in rails, and it has worked in the console, but I can't seem to implement it properly in views so that I am able to create more pictures for a single event (more explained below)

The background of the web application is, a single event has many event pictures, and many event pictures belong to a single event. I'm trying to set this up properly within the console and schematics, it seems to have worked. I was unable to get it working when I tried implementing it with views.

    <%= form_with(model: [ @event, @event.event_pictures.build ], local: true) do |form| %>
  <p>
    <%= form.label :answer %><br>
    <%= form.text_field :answer %>
  </p>
  <p>
    <%= form.label :hint %><br>
    <%= form.text_field :hint %>
  </p>
  <p>
    <%= form.label :event_pics %>
    <%= form.file_field :event_pics, multiple: true %>
  </p>
  <p>
    <%= form.submit %>
  </p>
<% end %>

The code above is my form which is the main cause of the issue. The error is shown below.

undefined method `event_pictures' for nil:NilClass

Console stuff works.. in Pastebin ( https://pastebin.com/ESYAfMzE )

Controller

def new
    render 'new'
  end
  def create
    @event = Event.find(params[:event_id])
    @event_picture = @event.event_pictures.create(event_picture_params)
    redirect_to event_path(@event_picture)
  end

**Button to create new picture, in Event Index, so you can see the event, before clicking on a button for a new picture. **

<%= button_to "new picture", {:controller => :event_picture, :action => 'new', :event_id => event.id},
              :method => :get,
              class: "btn btn-warning" %>

This is fairly frustrating as I've also looked into the possibility of using fields_for instead of form_with , and checked my schema.rb and migrations a number of times to make sure it is properly linked. At this point, I'd really appreciate any help at all as I've gone hours looking at this problem.

Thank you very much.

Answer 1

I see, in your new action, you need to setup the @event instance variable:

def new
  @event = Event.find(params[:event_id])
end