title: Unescaping HTML string
body: <p>I have the inherited the following string (I can do nothing about the format):</p>
  
  <pre><code> &amp;lt;iframe \n  class=\"some_class\"\n  type=\"text/html\" \n  src=\"/embed/iframe_content.html?id=tsqA5D7_z10\" \n  width=\"960\" \n  height=\"593\" \n  marginwidth=\"0\" \n  marginheight=\"0\" \n  frameborder=\"0\"&amp;gt;\n&amp;lt;/iframe&amp;gt;
  </code></pre>
  
  <p>I am rendering it in an erb template like this:</p>
  
  <pre><code>&lt;%= the_string %&gt;
  </code></pre>
  
  <p>At the moment it renders as text like this:</p>
  
  <pre><code>&amp;lt;iframe  class="some_class" type="text/html" src="/embed/iframe_content.html?id=tsqA5D7_z10" width="960" height="593"  marginwidth="0" marginheight="0" frameborder="0"&amp;gt;&amp;lt;/iframe&amp;gt;
  </code></pre>
  
  <p>I need to render it as HTML.</p>
  
  <p>I have tried the following:</p>
  
  <ol>
  <li><code>&lt;%= the_string.html_safe %&gt;</code>  # Renders the string unchanged</li>
  <li><code>&lt;%= CGI.unescapeHTML(the_string) %&gt;</code> # Errors with a Type Error 'can't dup NilClass'</li>
  <li><code>&lt;%= CGI.unescapeHTML(the_string).html_safe %&gt;</code> # Errors with a Type Error 'can't dup NilClass'</li>
  <li><code>&lt;%= raw the_string %&gt;</code> # Renders the string unchanged</li>
  </ol>
  
  <p>How can I render this string as HTML?</p>