title: materialize best practice validate empty field
body: <p>i use this form </p>
  
  <pre><code>&lt;div class="row"&gt;
      &lt;form class="col s12"&gt;
          &lt;div class="row"&gt;
              &lt;div class="input-field col s12"&gt;
                  &lt;input id="email2" type="email" class="validate"&gt;
                  &lt;label for="email2" data-error="wrong" data-success="right"&gt;Email&lt;/label&gt;
              &lt;/div&gt;
              &lt;div class="input-field col s12"&gt;
                  &lt;input id="example" name="example" type="text" class="validate" required="" aria-required="true"&gt;
                  &lt;label for="example" data-error="wrong" data-success="right"&gt;Field&lt;/label&gt;
              &lt;/div&gt;
          &lt;/div&gt;
      &lt;/form&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>mail field is ok. if I post in an incorrect mail address error message appears.</p>
  
  <p>example field not work. i would check if field is not empty and then show error.</p>
  
  <p>What's wrong?</p>