title: Permitting array of arrays with strong parameters in rails
body: <p>I have searched everywhere but does anyone know if it is possible to permit and array of arrays using strong parameters in rails? My code looks like this:</p>
  
  <pre><code>params.require(:resource).permit(:foo, :bar =&gt; [[:baz, :bend]])
  </code></pre>
  
  <p>This is giving me: </p>
  
  <blockquote>
    <p>ArgumentError (wrong number of arguments (0 for 1..2))</p>
  </blockquote>
  
  <p>I have also tried:</p>
  
  <pre><code>params.require(:resource).permit(:foo, :bar =&gt; [[]])
  params.require(:resource).permit(:foo, :bar =&gt; [][])
  params.require(:resource).permit(:foo, :bar =&gt; [])
  </code></pre>
  
  <p>But these all give me invalid parameter errors or do not process the parameters. </p>
  
  <p>Thanks in advance for any help</p>