Getting Rid of Nil Class Error in Ruby

Question

I currently have a table that is split into 4 columns as such:

  <table id="customers">
<tr>
  <th><em class='require'></em><%= Release.columns_hash['version'].human_name  -%></th>
  <th><em class='require'></em><%= Release.columns_hash['version'].human_name  -%></th>
  <th><em class='require'></em><%= Release.columns_hash['version'].human_name  -%></th>
  <th><em class='require'></em><%= Release.columns_hash['version'].human_name  -%></th>
</tr>
<% @releases.in_groups_of(4).each do |releasesplit| %>
<tr>
   <% releasesplit.each do |release| %>
   <td align="center"><%= release.version %></td>
   <% end %>
</tr>
<% end %>

However the problem is whenever I add another entry to the table that is not divisible by 4 I get the error: undefined method version' for nil:NilClass

Any Ideas how to fix this? Thanks,

Answer 1

It seems like one of your releases in @releases variable is nil.

You can do this: @releases.compact.in_groups_of(4).each do ...

Array#compact returns a copy of the original array with nil elements removed.

However, I strongly suggest you investigate why one of those is nil in the first place.

This is not the issue of grouping, since this is how grouping works:

irb(main):002:0> [1,2,3].each_slice(2) {|group| puts group.inspect}
[1, 2]
[3]
=> nil

(in_groups_of is just an ActiveSupport alias for each_slice)