带有另一个回复模型的Rails多态帖子导致路由问题

Question

I have a polymorphic model Post that make user able to leave a comment on different models.

and users are able to reply those Post in a Reply model which has text content only

It has no problem if a user want to leave a post on either Category or Subject page.but, if a user want to reply the post, it cause routing problem.

Here are 5 models (Category /Subject /Post /Reply /User)

The code are as following

Models

models/category.rb
class Category < ActiveRecord::Base
  has_many :subjects
  has_many :posts, as: :postable
end

models/subject.rb
class Subject < ActiveRecord::Base
  belongs_to :category
  has_many :posts, as: :postable
end

models/post.rb
class Post < ActiveRecord::Base
  belongs_to :user
  belongs_to :postable, polymorphic: true
  has_many :replies
end

models/reply.rb
class Reply < ApplicationRecord
  belongs_to :user
  belongs_to :post
end

And the controllers:

controller/categories_controller.rb
 def show
    @postable = @category
    @post = Post.new
    @reply = Reply.new
 end

controller/subjects_controller.rb
 def show
    @postable = @subject
    @post = Post.new
    @reply = Reply.new
 end

controller/posts_controller.rb
def create
   @post = @postable.posts.build(post_params)
   @post.user = current_user

  if @post.save
     @post.reload
     redirect_to @postable, notice: "Created"
  else
     render :new
  end
end

controller/replies_controller.rb
  def create
    @reply = @post.replies.build(reply_params)
    @reply.user = current_user     

    if @reply.save
      redirect_to :back
    else
      flash[:alert] = "Sorry, something went wrong."
      render user_path
    end
  end

views:

views/XXX/show.html.erb
 ....some content of Category or Subject show page...
       <% @posts.each do |post|%>
        <%= link_to post.user.username, post.user %>
        <%= simple_format post.content %>
        <%= render partial: "replies/reply", :locals => {:post => post} %>
       <% end %>  

 view/replies/_reply.html.erb
  <% if post.replies %>
    <% post.replies.each do |reply| %>
      <%= link_to reply.user.username, reply.user %>
      <%= simple_format reply.content %>
    <% end %>
  <% end %>   
  <%= simple_form_for :reply do |r| %>
    <%= r.hidden_field :post_id, value: post.id %>
    <%= r.input :content, label: false  %>   
    <%= r.button :submit, "Submit" %>          
  <% end %>  

I tried several ways in route.rb file

either
  resources :subjects do
    resources :posts do
      resources :replies
    end
  end  

or
resources :replies 

Once I submit a new reply of a post, it always shows the following result

No route matches [POST] "/subjects/82"

My question is what should I do on route.rb or other file to solve the problem?

Answer 1

You need to pass url with simple_form_for explicitly like this: -

  <%= simple_form_for :reply, :url => your_create_reply_path, :method => :post  do |r| %>
    <%= r.hidden_field :post_id, value: post.id %>
    <%= r.input :content, label: false  %>   
    <%= r.button :submit, "Submit" %>          
  <% end %>   

you can check url for create reply by command rake routes | grep replies rake routes | grep replies and also provide method type get or post