title: How to render a ndb StringProperty field as a textarea widget using wtforms on App Engine?
body: <p>Example code:</p>
  
  <pre><code># model
  class Foos(ndb.Model):
      bar = ndb.StringProperty()
  
  
  # handler
  class FoosHandler(BaseHandler):
      def get(self):
          form = model_form(Foos)
          self.render('form.html', form=form)
  
  # template
  {{ form.bar() }}
  </code></pre>
  
  <p>According to wtforms documentation, any StringProperty field that has the attribute "multiline=True" will be rendered with the TextArea widget.</p>
  
  <p>However, multiline=True is not supported in NDB (only DB) and so this doesn't work.</p>
  
  <p>Is there a way to specify what widget a field should be rendered with?</p>