Rails 4 routing error with nested comments form using nested resources

Question

I was following this tutorial http://www.sitepoint.com/nested-comments-rails/ to implement nested comments for an image board. It worked fine until I made "comments" belong to "boards" and then had to nest my routes.

Here are my routes:

Rails.application.routes.draw do
  root "boards#index"
  devise_for :users do
    get '/users/sign_out' => 'devise/sessions#destroy'
  end
  resources :boards do
    resources :comments
      get '/comments/new/(:parent_id)', to: 'comments#new', as: :new_comment
      get '/comments/(:parent_id)', to: 'comments#destroy', as: :delete_comment
      get '/comments/edit/(:parent_id)', to: 'comments#edit', as: :edit_comment
  end
end

Here is my form:

<%= form_for [@board, @comment] do |f| %>
  <% if @comment.errors.any? %>
    <div id="error_explanation">
      <h2><%= pluralize(@comment.errors.count, "error") %> prohibited this comment from being saved:</h2>

      <ul>
        <% @comment.errors.full_messages.each do |msg| %>
          <li><%= msg %></li>
        <% end %>
      </ul>
    </div>
  <% end %>

  <%= f.hidden_field :parent_id %>

  <div class="form-group">
    <% if @comment.parent_id == nil %>
    <%= f.label :title %>
    <%= f.text_field :title, class: 'form-control' %>
    <% else %>
    <% nil %>
    <% end %>
  </div>
  <div class="form-group">
    <%= f.radio_button(:user_id, current_user.id) %>
    <%= f.label(:user_id, "I want to post as myself") %>
    <%= f.radio_button(:user_id, nil) %>
    <%= f.label(:user_id, "I want to post anonymously") %>
  </div>

  <div class="form-group">
    <%= f.label :content %>
    <%= f.text_area :content, class: 'form-control', required: true %>
  </div>

  <div class="form-group">
  <%= f.label :image %>
  <%= f.file_field :image %>
  </div>

  <%= f.submit class: 'btn btn-primary' %>
<% end %>

And here is my controller:

class CommentsController < ApplicationController

  def index
    @comments = Comment.hash_tree
  end

  def new
    @comment = Comment.new(parent_id: params[:parent_id])
  end

  def edit
    @comment = Comment.find(params[:parent_id])
  end

  def create
    if params[:comment][:parent_id].to_i > 0
      parent = Comment.find_by_id(params[:comment].delete(:parent_id))
      @comment = parent.children.build(comment_params)
    else
      @comment = Comment.new(comment_params)
    end

    if @comment.save
      redirect_to root_url
    else
      render 'new'
    end
  end

  def update
    @comment = Comment.find(params[:id])
    if @comment.update(comment_params)
      redirect_to @comment
    else
      render 'edit'
    end
  end

  def make_parent
    @comment.parent_id = nil
    @comment.save
  end


  def destroy
    @comment = Comment.find(params[:parent_id])
    @comment.destroy

    respond_to do |format|
      format.html { redirect_to comments_url }
    end
    authorize! :destroy, @comment
  end

  private

  def comment_params
    params.require(:comment).permit(:title, :content, :user_id, :image)
  end
end

I've tried setting a custom route in the form, this gets the form to at least appear, however when you hit the submit button it returns 'No route matches [POST] "/boards/1/comments/new"'. If I got to the controller and then change the corresponding "get" to a "post" then it causes the form to just reappear after pressing submit and nothing is added to the database. I've also experimented with shallow nesting my routes as per my instructors advice but this didn't work.

Answer 1

Your association between boards and comments must be:

board.rb

has_many :comments

comment.rb

belongs_to :user

routes.rb

resources :boards do
resources :comments, only: [:new, :edit, :destroy]
end

this will create a route

new_board_comment   GET    /boards/:board_id/comments/new(.:format)      comments#new
edit_board_comment  GET    /boards/:board_id/comments/:id/edit(.:format) comments#edit
board_comment       DELETE /boards/:board_id/comments/:id(.:format)      comments#destroy