nested attribute pagination error (kaminari)

Question

I'm pretty sure that this is a simple fix but I'm not seeing it. I have an app where I'd like to show a music_videos comments. Below are my controllers:

def show
  @music_video = MusicVideo.find(params[:id])
  @comment = Comment.new
  @comments = @music_video.comments.page(params[:page]).per(3)
end

The above is my music video controller.

def create
@music_video = MusicVideo.find(params[:music_video_id])
@comment = @music_video.comments.build(comment_params)

  if @comment.save
    flash[:notice] = "Comment Submitted"
    redirect_to music_video_path(@music_video)
  else
    render 'music_videos/show'
  end
end

def destroy
  @comment = Comment.find(params[:id])
  @comment.destroy
  redirect_to root_path, notice: "Comment Deleted"
end

private
def comment_params
  params.require(:comment).permit(:body)
end

Above is my comments controller

Finally my show page:

<div class="comments_row">
  <% @music_video.comments.each do |comment| %>
    <% if user_signed_in? && current_user.admin? %>
     <p class="comment"><%= comment.body %></p>
      <%= link_to 'Delete Comment', music_video_comment_path(@music_video,comment),   
        method: :delete %>
      <% else %>
        <p class="comment"><%= comment.body %></p>
    <% end %>
  <%end%>
</div>
<%= paginate @comments %>

I'm pretty sure something is wrong with my controllers, but I'm not sure exactly what it is. @comments is in the correct controller (MusicVideo) within the correct CRUD operation (show). Currently I have six comments in a particular show page and the pagination shows up just fine but the six comments are not paginated. Any thoughts?

EDIT-------------

I figured out one the problem but stumbled on a new one. I figured out that in my controller I am declaring @comments = pagination etc. etc. when in my views there is no @comments to paginate. The problem is now that when I use

<%= paginate @comment %>

the code will break.the problem now that I'm having is what variable to paginate. Trying this code will also break

<%= paginate @music_video.comments %> 

Any recommendations?

Answer 1

I set up a test application using the kaminari gem for pagination. This is what my my music video controller's show action looks like:

  def show
    @music_video = MusicVideo.find(params[:id])
    @comments = @music_video.comments.page(params[:page]).per(3)
  end

And here is what my show view looks like:

<p id="notice"><%= notice %></p>

<p>
  <strong>Name:</strong> <%= @music_video.name %>
</p>

<% @comments.each do |comment| %>
  <p>
    Comment: <%= comment.text %>
  </p>
<% end %>

<%= paginate @comments %>

<%= link_to 'Edit', edit_music_video_path(@music_video) %> |
<%= link_to 'Back', music_videos_path %>

It is working and the pagination is showing up for me.

I think one thing i see directly is that you should use <% @comments.each do |comment| %> instead of <% @music_video.comments.each do |comment| %> because the way you have it now it will display all comments for the video regardless of what page you are on. If you had 6 comments and wanted 3 per page you would see the pagination with the two pages because you're running your pagination based off of @comments and you would end up seeing all 6 comments on both pages because you're doing your .each with @music_videos.comments.each.

So, at least using @comments in both places would be a start. And make sure you're using <%= paginate @comments %> for the pagination. If you use this in your controller and view what do you get? Do you see any comments?

Also, Ryan Bates has a great screencast on Kaminari as well: http://railscasts.com/episodes/254-pagination-with-kaminari (that site is a great resource for rails questions)