title: How to turn on/off a field from parsley.js form validation
body: <p><a href="https://i.stack.imgur.com/zMnal.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/zMnal.jpg" alt="enter image description here"></a>When validating an email field [name=bar] in a form #foo, I want to switch validation of that field on and off, in relation to a checkbox.</p>
  
  <p>Reading the docs, github issues and stackoverflow answers, I thought setting data-parsley-required="false" and/or data-parsley-validate="false" would be enough.</p>
  
  <p>But it turns out, that all other constraints, like email, min-lenght, max-length are still validated and the input field still validates to an error condition. I would prefer it to validate to success or not at all.</p>
  
  <pre><code>&lt;form id="foo"&gt;
      &lt;input name="bar"
             maxlength="40"
             value=""
             class="form-control"
             data-parsley-validate="false"
             data-parsley-required="false"
             type="email"
             data-parsley-minlength="5"
             data-parsley-trigger="input keyup change"
             data-parsley-error-message="something is wrong"&gt;
  &lt;/form&gt;
  </code></pre>
  
  <p>See <a href="https://jsfiddle.net/88obg0sj/9/" rel="nofollow noreferrer">https://jsfiddle.net/88obg0sj/9/</a></p>
  
  <p>So how is it possible to turn off field validation in way, it can be re-activated again?</p>