Rails mapping by max size and loop - ruby-on-rails

Question

In my rails application I'm looking to display in a table some results mapping by max size.
Controller
#max_length = [#result.generals, #result.measurements.in_groups_of(3)].map(&:size).max
The problem i'm facing is my #result.measurement has 3 dates for each measurement in which I want to display across the row.
This is what I'm looking to achieve:
But with the code below, this is my result - It stops at the first date:
How can I go about looping the #result.measurements?
<table>
<tr>
<th colspan="2">General</th>
<th colspan="6">Measurements</th>
</tr>
<tr>
<td>Number</td>
<td>Town</td>
<td>Date</td>
<td>Length</td>
<td>Date</td>
<td>Length</td>
<td>Date</td>
<td>Length</td>
</tr>
<% #max_length.times do |data| %>
<tr>
<td><%= #result.generals.[data].try(:number) %></td>
<td><%= #result.generals.[data].try(:town) %></td>
<td><%= #result.measurements.[data].try(:date) %></td>
<td><%= #result.measurements.[data].try(:length) %></td>
</tr>
<% end %>
</table>

Answer 1

Your code is doing exactly what you are asking it to do: to display a single td for the measurements. In order to have three lots of the columns, you need to loop over the data eg something like:
<table>
<tr>
<th colspan="2">General</th>
<th colspan="6">Measurements</th>
</tr>
<tr>
<td>Number</td>
<td>Town</td>
<td>Date</td>
<td>Length</td>
<td>Date</td>
<td>Length</td>
<td>Date</td>
<td>Length</td>
</tr>
<% #result.measurements.in_groups_of(3).each do |general, measurements| %>
<tr>
<td><%= general.try(:number) %></td>
<td><%= general.try(:town) %></td>
<% measurements.each do |m|
<td><%= m.try(:date) %></td>
<td><%= m.try(:length) %></td>
<% end %>
</tr>
<% end %>
</table>
Note: of course I have not bug-tested this - it will probably not work exactly as is - because I do not have a copy of your data (and you have not provided an example) so you'll need to adapt what I've written to what you have so that it works...
At present I don't know how your general relates to your measurements.
can you provide some example data that you would expect to be returned by the fetching-code and I can adapt this example to fit.