title: Django: forms.ChoiceField doesnt refresh after new page loading
body: <p>In my Django App, I wrote a form with a  <strong><em>forms.ChoiceField</em></strong> .  The choice should be a list of items that are changing every couple of minutes in my DB. I would like to have the current list of items  in a drop-down button when I reload the page. </p>
  
  <p>My code works good except the forms.ChoiceField does not update. To update I have to restart the Django server. </p>
  
  <p>I don't know what i am missing, Can you help me ? It must be something small.</p>
  
  <p>from forms.py</p>
  
  <pre><code>class BookingForm(forms.ModelForm):
      make_list_of_tuple = lambda list_machine  :  [tuple( [i,i]) for i in list_machine]
      MACHINES= tuple( QA_machine_DB.objects.values_list('QAmachine',flat=True))
      CHOICE_QA_MACHINES= make_list_of_tuple(MACHINES)
      QAmachine= forms.ChoiceField(choices=CHOICE_QA_MACHINES)
  
      class Meta():
          model= QA_machine_DB
          fields= ['QAmachine', 'owner', 'comments','status']
          # http://nanvel.name/2014/03/django-change-modelform-widget
          widgets = {
                     'owner':forms.TextInput(attrs={'placeholder':'owner'}),
                     'comments':forms.TextInput(attrs={'placeholder':'comments'}),
                     'status': forms.RadioSelect( choices=[('busy','busy'),('free','free')])}
  </code></pre>
  
  <p>from the template </p>
  
  <pre><code>&lt;form   class="form-group" method="post" novalidate &gt;
      {% csrf_token %}
       &lt;table &gt;
         &lt;td&gt;
            {{ BookingForm.QAmachine}}
          &lt;/td&gt;
           &lt;td&gt;
             {{ BookingForm.owner.errors }}
             {{ BookingForm.owner}}
           &lt;/td&gt;
           &lt;td&gt;
             {{ BookingForm.comments.errors }}
             {{ BookingForm.comments}}
           &lt;/td&gt;
           &lt;td&gt;
             {% for radio in BookingForm.status %}
             {{ radio }}
             {% endfor %}
           &lt;/td&gt;
      &lt;/table&gt;
    &lt;input type="submit" class="btn btn-success" value="submit status change" style="float: right;"     &gt; 
  </code></pre>
  
  <p></p>
  
  <p>Tank you in Adavance </p>