[Django]-Custom django widget – decompress() arg not populated

by

4👍

Note this line in the docstring for MultiWidget:

You’ll probably want to use this class with MultiValueField.

That’s the root of your problem. You might be able to get the single-widget-only approach working (Marty says it’s possible in Pro Django, but I’ve never tried it, and I think it’s likely to be more work), but in that case your widget shouldn’t be a subclass of MultiWidget.

What you need to do (if you want to follow the MultiWidget/MultiValueField path) is:

  • remove your value_from_datadict method
  • define a subclass of MultiValueField with a definition of the compress() method which does the task you’re currently doing in value_from_datadict() (transforming a list of numbers into a datetime.time object)
  • set your Widget as the default one for your custom form Field (using the widget class attribute)
  • either create a custom model Field which returns your custom form Field from its formfield() method, or use your custom form field manually as a field override in a ModelForm.

Then everything will Just Work.

👤Carl Meyer

0👍

I can’t reproduce the problem:

>>> class MyForm(forms.Form):
...     t = forms.TimeField(widget=MilitaryTimeWidget())
...
>>> print MyForm(data={'t_0': '13', 't_1': '34'})
******** 13:34:00
<tr><th><label for="id_t_0">T:</label></th><td><select name="t_0" id="id_t_0">
<option value="0">00</option>
[...]
<option value="13" selected="selected">13</option>
[...]
<option value="23">23</option>
</select><select name="t_1" id="id_t_1">
<option value="0">00</option>
[...]
<option value="34" selected="selected">34</option>
[...]
<option value="59">59</option>
</select></td></tr>

Check that your request.POST is correct.

As a sidenote, are you sure this widget gives good usability? Four mouse clicks and possible scrolling of the minutes combobox…

👤akaihola

Leave a comment