title: Rails simple_form: custom input id
body: <p>I want to put several forms generated with Rails simple_form on a one page, and operate on them with javascript. However simple_form generated same ids for respective inputs in forms. Thus I want to replace generated id with my own.</p>
  
  <p>Now I have a line:</p>
  
  <pre><code>&lt;%= f.input :id, :as =&gt; :hidden, :html =&gt; {:value =&gt; @question.id} %&gt;
  </code></pre>
  
  <p>and HTML output (for @question.id=1):</p>
  
  <pre><code>&lt;input id="question_id" class="hidden" type="hidden" value="1" name="question[id]"&gt;
  </code></pre>
  
  <p>and I want to get:</p>
  
  <pre><code>&lt;input id="question_id_1" class="hidden" type="hidden" value="1" name="question[id]"&gt;
  </code></pre>
  
  <p><code>question_id_1</code> is just an example. I want to be able to choose this id.</p>
  
  <p>I use Rails 3 and simple_form 1.5.</p>