Question

Following up on a previous question, I have a few issues to resolve before I have a comment form showing and submitting securely on my profile. I’m a beginner to programming so thinking across multiple controllers seems to have me lost.

What I’m doing is posting comments in a form, then listing them.

Background: The _comment_form and _comment reside as partials in the Profile about. (My next task is toggling from about to other Profile information, but that’s another question altogether.)

Using the help provided in my last question I feel like I’m almost there but am getting an error.

CreateComments migration:

t.integer :profile_id
t.integer :author_id
t.string :body

My Comment model:

class Comment < ActiveRecord::Base
  belongs_to :profile
  belongs_to :author, :class_name =>"User", :foreign_key => "author_id"
end

CommentsController:

def create
  @comment = Comment.new(params[:comment].merge(:author_id => current_user.id))
  @comment.save!
  redirect_to profile_path(@comment.profile)
end

ProfilesController:

def create
  @profile = Profile.new(params[:profile])
  if @profile.save
    redirect_to profile_path(@profile), :notice => 'User successfully added.'
  else
    render :action => 'new'
  end
end

def show
  @user = User.find(params[:id])
  @profile = @user.profile
  @comment = @profile.comments.new
end

Comment partials inside Profile partial:

<div id="commentEntry">
  <%= render :partial => 'comment', :collection => @profile.comments %>
</div>
<div id="newitem">
  <%= render :partial => 'comment_form' %>
</div>

Routes.rb:

resources :users do
  resources :profiles
end
resources :comments

_comment_form.html.erb:

<%= form_for @comment do |f| %>
  <%= f.text_field :body %>
  <%= f.submit 'Add new' %>
<% end %>

_comment.html.erb:

<li class="comment" title="<%= @comment.author.profile.first_name %> <%= @comment.author.profile.last_name %>">
  <%= @comment.body %>
</li>

So, Issue #1: Wrapping the _comment.html.erb in a loop <% for @comment in @user.profile.comments %> shows the profile but when I try and submit a new comment I get “Unknown action The action ‘update’ could not be found for CommentsController”. If I take away the loop, the profile doesn’t show and I get “NoMethodError in Profiles#show undefined method `profile’ for nil:NilClass”. Can anyone help me out and explain what I’m doing wrong?

Issue #2: I created a sample comment in rails console and when I get the profile to show, the input field for comment :body repopulates with the comment’s body. Any ideas on what could be going on?

Answer 1

Short explanation of your problem:

The @comment you’re getting in your _comment_form partial is one that’s already saved in your database, hence the call to the update action and the body that’s already filled.

You’re creating the new comment just fine with @comment = @profile.comments.new in your show action, but it gets overridden somewhere else.

You’re mentioning that you wrapped the _comment render in a loop with <% for @comment in @user.profile.comments %>, the problem is most likely there.

Fix:

The only thing you should have to change is the _comment partial to (without the for loop that you added):

<li class="comment" title="<%= comment.author.profile.first_name %> <%= comment.author.profile.last_name %>">
  <%= comment.body %>
</li>

When you do the render :partial => 'comment', :collection => @profile.comments, rails is smart enough to loop over @profile.comments and give the comment (not @comment) variable to the partial.

How to avoid this the next time:

I’ll give you two rules of thumb to avoid getting in this situation:

1. Try to name your variables more precisely. @new_comment would have been a better name for the variable to store the new comment. @comment is a bit ambigous as you’ve got a boatload of those in your view.

2. Avoid creating and modifying instance variables (@ variables) in your views, try to do this only in your controller. I’ll admit your particular case was a bit harder to detect because of the <% for @comment in @user.profile.comments %>. The view got its name for a good reason, it’s only supposed to let you view the data you’ve defined in your controller.

Hope this helps.