title: How to get all checked items in SelectMultipleField in WTForms + Flask
body: <p>I have a <code>SelectMultipleField</code> but when I try to access checked items, thought <code>form.fields.data</code> I only get the first of them.
  More over, by trying to get answers directly from <code>request.form.data</code> through</p>
  <pre><code>        for key in request.form.keys():
              print(str(key) + '=' + str(request.form.getlist(key)))
  </code></pre>
  <p>I can see an array of all checked items there.</p>
  <p>Where have I made a mistake, so WTForms can't pass all checked items to <code>form.fields.data</code>?</p>
  <p>My route:</p>
  <pre><code>    form = ListForm()
  
      if request.method == &quot;GET&quot;:
          form.add_items(bank.get_items())
      elif request.method == &quot;POST&quot;:
          print(form.fields.data) # and in needed field i only see 'A' even if 'A', 'B' and 'C' checked
  </code></pre>
  <p>form itself:</p>
  <pre><code>class Item(FlaskForm):
      pass
  
  class ListForm(FlaskForm):
      fields = FieldList(FormField(Item))
      submit = SubmitField('Submit')
  
      def add_items(self, items):
          for item in items:
              Item.choices_field = SelectMultipleField(
                  choices=item.get_choices()
              ) # lets just assume get_choices() returned ['A', 'B', 'C', 'D'] for an element
  
              self.fields.append_entry()
  </code></pre>
  <p>and my template for it:</p>
  <pre><code>        {{ form.hidden_tag() }}
          &lt;form method=&quot;post&quot; novalidate&gt;
                  {% for field in form.fields %}
                          &lt;fieldset&gt;
                                 {{ field.choices_field }}
                          &lt;/fieldset&gt;
                  {% endfor %}
                  {{ form.submit }}
          &lt;/form&gt;
  </code></pre>
  <p>I tried using tuples instead of list of options but had the same issue</p>