Adding Comments to multiple models - ruby-on-rails

Question

Im trying to add comments to my topics model the same way you can add comments to posts on my app. i currently have to partials for comments _comment.html.erb and _form.html.erb
_comment :
<%= content_tag :div, class: 'media', id: "comment-#{comment.id}" do %>
<div class= "media">
<div class= "media-body">
<small>
<%= comment.user.name %> commented <%= time_ago_in_words(comment.created_at) %> ago
<% if user_is_authorized_for_comment?(comment) %>
| <%= link_to "Delete", [comment.post, comment], method: :delete %>
<% end %>
</small>
<p> <%= comment.body %></p>
</div>
</div>
<% end %>
_form :
<h4>Add a comment</h4>
<%= form_for [post, comment] do |f| %>
<div class="form-group">
<%= f.label :body, class: 'sr-only' %>
<%= f.text_field :body, class: 'form-control', placeholder: "Enter a new comment" %>
</div>
<%= f.submit "Submit Comment", class: 'btn btn-default pull-right' %>
<% end %>
my topic show is :
#DISPLAY Topic comments here
<h3> Comments</h3>
<%= render #topic.comments %>
</div>
<% if current_user %>
<%= render 'comments/form', comment: Comment.new, post: #post %>
<% end %>
#------
comment controller :
def create
#post = Post.find(params[:post_id])
comment = #post.comments.new(comment_params)
comment.user = current_user
if comment.save
flash[:notice] = "Comment saved successfully."
redirect_to [#post.topic, #post]
else
flash[:alert] = "Comment failed to save."
redirect_to [#post.topic, #post]
end
end
def destroy
#post = Post.find(params[:post_id])
comment = #post.comments.find(params[:id])
if comment.destroy
flash[:notice] = "Comment was deleted"
redirect_to [#post.topic, #post]
end
end
i have updated the routes for topic comments :
resources :topics do
resources :posts, except: [:index]
resources :comments, only: [:create, :destroy]
end
my question is do i need to create a separate partial to add comments to topics or can i update my _comment partial to work for both post and topic comments . and how can i accomplish this ?

Answer 1

Models
You'll need a polymorphic association on the Comment model:
#app/models/comment.rb
class Comment < ActiveRecord::Base
belongs_to :commentable, polymorphic: true
end
#app/models/topic.rb
class Topic < ActiveRecord::Base
has_many :comments, as: :commentable
end
#app/models/post.rb
class Post < ActiveRecord::Base
has_many :comments, as: :commentable
end
Controllers
This will allow you to save the comments for your various models, the controllers / flow coming secondary:
#config/routes.rb
resources :topics, :posts do
resources :comments, only: [:create, :destroy] #-> url.com/topics/:topic_id/comments
end
#app/controllers/comments_controller.rb
class CommentsController < ApplicationController
def create
id = params[:post_id] || params[:topic_id]
if params[:post_id]
#parent = Post.find id
elsif params[:topic_id]
#parent = Topic.find id
end
#comment = #parent.comments.find params[:id]
#comment.save
end
def destroy
#parent = params[:post_id] || params[:topic_id]
#comment = #parent.comments.new comment_params
#comment.destroy
end
private
def comment_params
params.require(:comment).permit(:x, :y)
end
end
Because you're passing the data to the comments controller, you'll only need to evaluate which #parent you're working with.
Views
For your views, you need to pass locals to your _form partial:
#app/views/posts/show.html.erb
<%= render "comments/form", locals: {parent: #post} %>
#app/views/comments/_form.html.erb
<%= form_for [parent, parent.comments.new] do |f| %>

Answer 2

I had this road-block as well and here is what I came up with that passed. I must first give #Richard Peck applause for getting my wheels turning, so thank you :).
Models
Did not implement a polymorphic association. Stuck with has_many and belongs_to, nothing more
Partials
_comment.html.erb
Set up the delete partial to accept "parent" as a local
<div class="media">
<div class="media-body">
<small>
<%= comment.user.name %>
commented
<%= time_ago_in_words(comment.created_at) %>
ago
<% if user_is_authorized_for_comment_via_post?(comment) %>
|
<%= link_to "Delete", [parent, comment], method: :delete %>
<% end %>
</small>
<p>
<%= comment.body %>
</p>
</div>
</div>
_form.html.erb
same idea as _comment.html.erb, see above
<h4>Add a comment</h4>
<%= form_for [parent, comment] do |f| %>
<div class="form-group">
<%= f.label :body, class: 'sr-only' %>
<%= f.text_field :body, class: 'form-control', placeholder: "Enter a new comment" %>
</div>
<%= f.submit "Submit Comment", class: 'btn btn-default pull-right' %>
<% end %>
Setting up CommentController
...
def create
# upon clicking on create, determine what param id is passed
if params[:post_id]
# if it is a post id, set instance of post id as #parent
#parent = Post.find(params[:post_id])
elsif params[:topic_id]
# if it is a topic id, set instance of topic id as #parent
#parent = Topic.find(params[:topic_id])
end
# create instance as #comment. Build/create
# comment belonging to #parent (Topic or Post)
#comment = #parent.comments.build(comment_params)
# The comment must be associated to the current user.
# A comment must have a user, and value of user within instance of #comment
# is currently nil. Set user id as current user
#comment.user = current_user
# save comment to database
if #comment.save
# direction of save through if and elsif
# Redirection depends on the comment's parent.
# .is_a? method determines if it is of a certain class. Here, is #parent
# of class Post? Is #parents is the same parent id passed through params?
if #parent.is_a?(Post) # template error with this included: (== params[:post_id])
flash[:notice] = 'Comment saved successfully'
redirect_to [#parent.topic, #parent]
# if not part of the class Post, is it a Topic? If so, save here and
# redirect to the topic after save
elsif #parent.is_a?(Topic)
flash[:notice] = 'Comment saved successfully'
redirect_to #parent
end
end
end
def destroy
comment = Comment.find(params[:id])
# #topic = Topic.find(params[:topic_id])
# topic_comment = #topic.comments.find(params[:id])
# #post = Post.find(params[:post_id])
# post_comment = #post.comments.find(params[:id])
if comment.destroy
flash[:notice] = 'Comment was deleted'
redirect_to :back
else
flash[:alert] = "Comment counld't be deleted. Try again"
redirect_to :back
end
end
...
Passing in Comments from topic/show and post/show
topic/show
Note: notice how locals are passed into the controller from here
...
<div class="row">
<%= render 'comments/form', comment: Comment.new, parent: #topic %>
</div>
<% #topic.comments.each do |comment| %>
<%= render partial: 'comments/comment', locals: { parent: #topic, comment: comment } %>
<% end %>
...
post/show
<% if current_user %>
<% #post.comments.each do |comment| %>
<%= render partial: 'comments/comment', locals: { parent: #post, comment: comment } %>
<% end %>
<% end %>
<% if current_user %>
<%= render 'comments/form', comment: Comment.new, parent: #post %>
<% end %>
Hope this helps.