Issue with a nested form_for's parameter - ruby-on-rails

Question

I'm creating a website on which people can read mangas, thanks to three scaffolds : one for the manga itself, one for its chapters and a last one for the chapter's pages. In my routes.rb file, I nested the pages inside the chapter resources, which I nested inside the manga's, so my routes look like the following:
resources :mangas do
resources :chapters do
resources :pejis #Rails doesn't like the "scan" word
end
end
I can create a manga without troubles, but for an unknown reason, I can't manage to make the form appear:
views/chapters/_form.html.erb
<%= form_for(chapter) do |f| %>
<div class="field">
<%= f.label :titre %>
<%= f.text_field :titre %>
</div>
<div class="field">
<%= f.label :apercu %>
<%= f.file_field :apercu %>
</div>
<div class="field">
<!-- Allows me to upload the chapter's pages in the same time -->
<label for="images[]">Multi Upload</label>
<%= file_field_tag 'images[]', type: :file, multiple: true %>
</div>
<div class="actions">
<%= f.submit %>
</div>
<% end %>
The form_for parameter is as it was when created by the scaffold command. However, obviously, it doesn't work since I nested the resources inside the manga scaffold. I tried a few things, until new_manga_chapter_path allowed me to see the form. However, when submitting it, I'm getting the following error:
No route matches [POST] "/mangas/1/chapters/new". I'm not even sure if this is normal or strange.
I'm pretty sure I shouldn't put "new_manga_chapter_path" as parameter for the form_for but I have no idea what to put instead.
Just in case, here is the chapter controller:
class ChaptersController < ApplicationController
before_action :set_chapter, only: [:show, :edit, :update, :destroy]
def index
#chapters = Chapter.all
end
def show
end
def new
#chapter = Chapter.new
end
def edit
end
def create
#chapter = Chapter.new(chapter_params)
if #chapter.save
(params[:images] || []).each_with_index do |image, index|
#chapter.pejis.create(image: image, scan_number: index + 1)
end
redirect_to #chapter, notice: 'Chapter was successfully created.'
else
render :new
end
end
def update
if #chapter.update(chapter_params)
(params[:images] || []).each_with_index do |image, index|
#chapter.pejis.create(image: image, scan_number: index + 1)
end
redirect_to #chapter, notice: 'Chapter was successfully updated.'
else
render :edit
end
end
def destroy
#chapter.destroy
redirect_to chapters_url, notice: 'Chapter was successfully destroyed.'
end
private
def set_chapter
#chapter = Chapter.friendly.find(params[:id])
end
def chapter_params
params.require(:chapter).permit(:titre, :apercu)
end
end
Don't hesitate if you want to see something else
Thank you in advance

Answer 1

Try this:
# don't replace the [] by ()
<%= form_for [#manga, #chapter] do |f| %>
Or
<%= form_for manga_chapter_path(#manga, #chapter) %>
And in your controller:
def new
#manga = Manga.find(params[:manga_id])
#chapter = Chapter.new
end
To help you after your comments:
In your create method:
def create
#manga = Manga.find(params[:manga_id])
#chapter = Chapter.new(chapter_params)
if #chapter.save
(params[:images] || []).each_with_index do |image, index|
#chapter.pejis.create(image: image, scan_number: index + 1)
end
redirect_to manga_chapter_path(#manga, #chapter), notice: 'Chapter was successfully created.'
else
render :new
end
end