form_for on commentables in rails

Question

I'm having problems with the "First argument in form cannot contain nil or be empty" error that I haven't been able to find an answer for.

Basically, I have Posts, which show up on a User's show page, which should each have the option to comment on them. My routes are as follows:

 resources :posts,         only: [:create, :destroy] do
    resources :comments,    only: [:create, :destroy]
 end

users/show.html.erb

 <ol class="posts">
    <%= render @posts %>
 </ol>

posts/_post.html.erb

<li>
  <span class="content"><%= post.content %></span>
  <span class="timestamp">
     Posted <%= time_ago_in_words(post.created_at) %> ago.
  </span>
  <% if current_user?(post.user) %>
    <%= link_to "delete", post,         method: :delete,
                                data: { confirm: "You sure?" },
                                title: post.content %>
  <% end %>
  <span class="content">
    <ul> Comments: <%= post.comments.count %></ul>
<% post.comments.each do |comment| %>
        <ul> <%= comment.comment %> </ul> 
<% end %>
  </span>

  <% if post != nil %>
      <% form_for [post, @comment] do |f| %>
          <%= render 'shared/error_messages', object: f.object %>
        <div class="field">
            <%= f.text_area :content, placeholder: "Comment..." %>
        </div>
        <%= f.submit "Post", class: "btn btn-lg btn-primary" %>
        <% end %>
    <% end %>
</li>

s comments_controller.rb

def create
    @post = Post.find(params[:id])
    @comment = @post.comments.build(comment_params)
    @comment.user = current_user
    if @comment.save
      flash[:success] = "Posted!"
      redirect_to @post
    else
      render 'static_pages/home'
    end
end

def destroy
  @comment.destroy
  redirect_to root_url
end

Showing C:/app/views/posts/_post.html.erb where line #21 raised: (line 21 is the form_for line) First argument in form cannot contain nil or be empty app/views/posts/_post.html.erb:21:in _app_views_posts__post_html_erb___306000501_37434348' app/views/users/show.html.erb:19:in_app_views_users_show_html_erb__480533737_37130988'

If each post had a show page, I know that I would put @posts on the show action and then make it an instance variable, but since the each post needs a separate comment dialogue box, I can't make it that general. It doesn't go through the posts controller though so I can't make it specific to each post. I'm using acts_as_commentable for the comments. Ideally, I would like to make them generic and put all the form_for comment stuff into a partial, but I'll figure that out later.

form_for on commentables in rails

0 Answers0