title: Append WTForms FieldList without page refresh or loseing FileData? Ajax?
body: <p>I have a field list working. Problem is that every time it appends an entry it has to refresh the page. Refreshing the page makes the <em>FileField</em> data  disappear and the user has to reselect the file they want to upload every time they append and entry.</p>
  
  <p>I Was wondering if you could maybe ajax the field list into the page. Or some type of other solution to solve this problem. Maybe rewrite the field List into jquery? Is there any <em>python</em> or <em>Flask</em> or <em>WTForms</em> way to do it? 
  <br><br>
  Sample code of field list below</p>
  
  <pre><code>class SizeVariationForm(Form):
      name = TextField("name")
      sku = TextField("SKU Number")
  
  
  class AddVariationForm(NewListingForm):
      item_list = FieldList(FormField(SizeVariationForm))
      add_field = SubmitField('Add Variations')
      FileField('Main image 1')
  
  
  @app.route('/index', methods=['GET', 'POST'])
  def add_inputs():
      form = AddVariationForm(request.form)
      if form.add_field.data:
          new_variation = form.item_list.append_entry()
          return render_template('index.html',form=form)
  </code></pre>