How to show wtform validation error on modal

Question

I have a WTF Form inside a Twitter Bootstrap 3 modal, which I need to validate. The problem is that the modal closes when the user submits the form, even if there are validation errors. If I click on the button that triggers the modal again, the validation error is displayed. So my question is, how do I get the modal to stay open when there are validation errors? Thanks!

<button type="button" class="btn btn-default" data-toggle="modal" role="dialog" data-target="#save"> 
<span class="glyphicon glyphicon-flash"></span>
</button>


<div class="modal fade" id="save" tabindex="-1" role="dialog" aria-labelledby="myModalLabel" aria-hidden="true">
<div class="modal-dialog">
  <div class="modal-content">
   <div class="modal-header">
     <button type="button" class="close" data-dismiss="modal" aria-hidden="true">&times;</button>
     <h3 class="modal-title" id="myModalLabel">Archive List and Start New</h3>
    </div>

   <form role="form_list" class="form form-medium" action="." method="post">
   {{ form_save.csrf_token }}
    <div class="modal-body">    
        <h4>Save list as: </h4>
        {{ render_field(form_save.list_name, class="input-large") }}
    </div>

    <div class="modal-footer">
        <button type="button" class="btn btn-default" data-dismiss="modal">Close</button>
        <a href="#">
          <button class="btn btn-success">Archive List</button></a> 
    </div>
  </form>

  </div><!-- modal content -->
  </div><!-- modal-dialog -->
</div><!-- modal -->


<script src="{{ url_for('static', filename='js/jquery.js') }}"></script>
<script src="{{ url_for('static', filename='js/bootstrap.min.js') }}"></script>

Answer 1

You should add some javascript to automatically open the modal when there are errors from the form.

Something like (with jQuery):

var formErrors = {% if form_errors %}true{% else %}false{% endif %};

$(document).ready(function() {
    if (formErrors) {
        $('.modal').modal('show');
    }
});