NilClass in Partial

rubyonrails-talk
1

I appreciate your help in advance; I feel like the issue is staring me in the face!

I have two models: event and topic

/models/event.rb: class Event < ActiveRecord::Base   ..   has_many :topics   ..

/models/topic.rb: class Topic < ActiveRecord::Base   belongs_to :event end

I'm successfully showing the dependent topics with the event: /views/events/show.html.erb:

.. <table> <%@event.topics.each do |topic| %> <tr>   <td> <%= topic.Name %> </td>   <td> <%= topic.Description %></td> </tr> <% end %> </table> ..

When I attempt to edit the record that I can successfully show, I get:

Showing /views/events/_topic.html.erb where line #2 raised:

undefined method `new_record?' for nil:NilClass Extracted source (around line #2):

1: <div class="topic"> 2: <% new_or_existing = topic.new_record? ? 'new': 'existing' %> 3: <% prefix = "event[#{new_or_existing}_topic_attributes]"%> 4: 5: <% fields_for prefix, topic do |topic_form| -%>

The partial is rendered in edit.html.erb:

<h1>Editing tag</h1>

<%= render 'form' %>       <div id="topicContentArea">         <%= render 'topic', :collection => @event.topics %>       </div> <%= link_to 'Show', @event %> | <%= link_to 'Back', events_path %>

Ideas are appreciated! Thanks, Karl

2

I have not used :collection to pass something like @event.topics rather than a simple variable such as @topics, so wonder whether this works as you expect. You could try <%= render 'topic', :collection => @event.topics, :as => :topic %> in order to force the variable name in the partial.

Colin