unable to save multiple values via Django Form - django

Question

The post request is sending multiple values with same key e.g. values=foo&values=bar
I am seeing only one value in request object in both Django view and form. Not sure what I need to do to get multiple values in Django request object.
// model
class AttributeInstance(models.Model):
somefilter = models.CharField(max_length=255, blank=True)
values = models.TextField()
//form
class ABCModelForm(forms.ModelForm):
class Meta:
model = ABCModel
fields = ('somefilter', 'value')
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
if not self.data:
self.fields['values'] = forms.MultipleChoiceField(())
// view
class ABCModelView(FormView):
def get(self, request):
form = ABCModelForm()
return render(self.request, 'core/abc_model_edit.html', {'form': form})
def post(self, request):
try:
form = ABCModelForm(request.POST)
form.save()
form = ABCModelForm()
return render(self.request, 'core/abc_model_edit.html', {'form': form})
except Exception as e:
return HttpResponse(status='400')
<!-- HTML -->
<!-- fills the multiple choice field on runtime based on somefilter -->
<!-- the multiple choice UI element looks like below after rendering -->
<form method="post" id="abcModelForm" novalidate="">
<input type="hidden" name="csrfmiddlewaretoken" value="abcdcdcd">
<table>
<tbody>
<tr>
<th><label for="id_somefilter">Description:</label></th>
<td><input type="text" name="somefilter" maxlength="255" id="id_somefilter"></td>
</tr>
<tr>
<th>
<label for="id_values">Values:</label>
</th>
<td>
<select name="values" required="" id="id_values" multiple="multiple">
<option value="dodo">dodo</option>
<option value="bobo">bobo</option>
<option value="foo">foo</option>
<option value="bar">bar</option>
</select>
</td>
</tr>
</tbody>
</table>
<button type="submit">Save</button>
</form>

Answer 1

Its frustrating to know that Django doesn't seem to handle multiple values in form data gracefully.
I used Intellij debugger to inspect request.POST. I could see multiple values in a list for key values but QueryDict as the name suggest seems to understand that there can be only one value for a key and drops the remaining values. For now I have added following hack but not very happy with it. Still looking for a cleaner solution.
payload = dict(request.POST)
payload = {
key: (value if key == 'values' else value[0])
for key, value in payload.items()
}
queryDict = QueryDict(json.dumps(payload))
form = AttributeInstanceForm(queryDict)
// this is how payload looks after conversion from QueryDict
{
'description': ['hmm'],
'values': ['foo', 'bar', 'gogo']
}
I am using Content-Type: application/x-www-form-urlencoded