How display selected Key of a serialized Hash?

Question

I have a serialized hash of a checkbox, and i would like to display just the selected keys.

Model

class Policy < ActiveRecord::Base
  belongs_to :user
  serialize :shipping, JSON
end

View

<ul>
  <%= p.fields_for :shipping, @policy.shipping  do |s|%>
  <li><%= s.check_box :fedex %><%= s.label :fedex %></li>
  <li><%= s.check_box :dhl %><%= s.label :dhl %></li>
  <li><%= s.check_box :usps_10 %><%= s.label :usps %></li>
  </ul>
<% end %>

BD

{"fedex":"1","usps":"0","dhl":"0"}

View Show

<ul>
    <% if [email protected]? %>
      <% @policy.shipping.keys.each do |key|%>
        <li><%= key %></li>
      <% end %>
    <% end %>
</ul>

Answer 1

Your @policy.shipping should be a plain old Hash so select should sort you out:

<ul>
  <% if @policy.shipping.present? %>
    <% @policy.shipping.select { |k, v| v == 1 }.keys.each do |key| %>
      <li><%= key %></li>
    <% end %>
  <% end %>
</ul>

I'm not sure off the top of my head if you'll get 1 or '1' in your values though so you might need to v == '1' inside the select block.

You can skip the .present? (or !...nil?) check by taking advantage of the fact that nil.to_a is [] as well:

<ul>
  <% @policy.shipping.to_a.select { |k, v| v == 1 }.map(&:first).each do |key| %>
    <li><%= key %></li>
  <% end %>
</ul>

Or even:

<ul>
  <% @policy.shipping.to_a.select { |k, v| v == 1 }.each do |a| %>
    <li><%= a.first %></li>
  <% end %>
</ul>

And you probably want to fix your original view to be properly nested or you might run into strange things in the future:

<ul>
  <%= p.fields_for :shipping, @policy.shipping  do |s|%>
    <li><%= s.check_box :fedex %><%= s.label :fedex %></li>
    <li><%= s.check_box :dhl %><%= s.label :dhl %></li>
    <li><%= s.check_box :usps_10 %><%= s.label :usps %></li>
  <% end %>
</ul>