jquery validaiton plugin not working with file input
<p>I have added class <code>required</code> to the file input and called the validation method but it does not work.   </p>

<pre><code> &lt;form enctype="multipart/form-data" id="csvform" accept-charset="UTF-8" action="" method="POST" novalidate="novalidate"&gt;&lt;input type="hidden" value="xxgzK81sfXh2IYsKG6zTwmKqRk87jXuJ3uQpb2J4" name="_token"&gt;

                    &lt;input type="file" name="csv" id="csvform2" class="required" aria-required="true"&gt;

                    &lt;input type="hidden" value="15" name="vendorID"&gt;
                    &lt;br&gt;
                    &lt;button&gt;Add CSV&lt;/button&gt;

                    &lt;/form&gt;

$( "#csvform" ).validate();
</code></pre>