Question

I got two models: Post and Comment. Comment is a nested resource of Post:

routes.rb:

  resources :posts do
    resources :comments
  end

I’m enabling users to edit the comments that are displayed in the post show view:

posts/show.hmtl.erb:

  <%= render @comments %>

comments/_comment.html.erb:

<%= link_to "Edit Post Comment", edit_post_comment_path(@post, comment) %>

This form:

comments/_form.html.erb:

<h4>Add a comment:</h4>

<%= form_for([@post, @post.comments.build]) do |f| %>
  <div class="field">
    <%= f.label :content %><br />
    <%= f.text_area :content %>
  </div>
  <div class="actions">
    <%= f.submit %>
  </div>
<% end %>

<% unless current_user == nil %>
  <% if current_user.id == @post.user_id %>
    <%= link_to 'Edit', edit_post_path(@post) %> |
  <% end %>
<% end %>
<%= link_to 'Back', posts_path %>

Is for creating a comment in the show view.

I need another form to edit the comment in a new template:

comments/edit.html.erb:

<h1>Edit comment</h1>

<%= render 'form2' %>

<%= link_to 'Back', posts_path %>

comments/form2.html.erb:

<h4>Edit comment:</h4>

<%= form_for() do |f| %>
  <div class="field">
    <%= f.label :content %><br />
    <%= f.text_area :content %>
  </div>
  <div class="actions">
    <%= f.submit %>
  </div>
<% end %>

<%= link_to 'Back', posts_path %>

Not sure what to place here:

<%= form_for(HERE) do |f| %>

Any suggestions?

EDIT

comments_controller.rb:

class CommentsController < ApplicationController
  def show
    @comment = Comment.find(params[:id])
  end

  def new
    @comment = Comment.new
  end

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

 def update
    @post = Post.find(params[:post_id])
    @comment = Comment.find(params[:id])
    @comment.update_attributes(params[:comment])
    redirect_to @post
  end

  def create
    @post = Post.find(params[:post_id])
    comment_attr = params[:comment].merge :user_id => current_user.id
    @comment = @post.comments.create(comment_attr)
    redirect_to post_path(@post)
  end
end

Answer 1

Comments are nested resources and that means a comment is always tied to a particular Post. In the edit action you’ll get both comment_id and post_id as parameters. You should load both comment and post by those id’s. Don’t build the comment in the form to reuse the form for both new and edit actions. Change your form to:

comments/_form.html.erb

<%= form_for([@post, @comment]) do |f| %>

comments_controller.rb

def edit
  @comment = Comment.find(params[:id])
  @post = Post.find(params[:post_id])
end

and in the posts_controller.rb

def show
  @post = Post.find(params[:id])
  @comment = @post.comments.build
end