title: Rails (ruby) create empty array when no association found
body: <p>So I have this bit of code:</p>
  
  <pre><code>= f.input :aspectRatioId, :label =&gt; 'Aspect Ratio', 
  :input_html =&gt; { :id =&gt; 'dvd_aspectRatio_tokens', :data =&gt; { :load =&gt; [@dvd.aspectRatio] } }
  </code></pre>
  
  <p>I'd like to create an empty array when nothing is found in the association. Right now when nothing is found it returns <code>[null]</code> which trips up tokeninoput javascript that expects <code>[]</code></p>
  
  <p>I can do this by creating another method like this:</p>
  
  <pre><code>def self.series_without_empty_values(dvd)
    series = [dvd.dvd_series]
    if series[0].nil?
      series = []
    end
    return series
  end
  </code></pre>
  
  <p>But I would rather do it in the <code>:load =&gt;</code> call on the form. Is this even possible?</p>