Add PartialDateForm

[RafifEL]

I think we need a PartialDateField in forms because of PartialDateField for models exist.

[lorinkoz]

How do you envision it?

[RafifEL]

How do you envision it?

I'm thinking that we have to create Custom Form field PartialDateField that receive ISO Format date that create cleaned_data in form of PartialDateField Object

[SamuelJennings]

I wrote a custom form widget with a nicer UI for PartialDate fields based on Django's SelectDateWidget.

The code looks like this:

class PartialDateWidget(forms.SelectDateWidget):
  def get_context(self, name, value, attrs):
      # reorder the subwidgets to year, month, day
      context = super().get_context(name, value, attrs)
      m, d, y = context["widget"]["subwidgets"]
      context["widget"]["subwidgets"] = [y, m, d]
      return context

  def format_value(self, value):
      # convert PartialDate to dict for SelectDateWidget
      if isinstance(value, PartialDate):
          return {
              "year": value.date.year,
              "month": value.date.month if value.precision >= PartialDate.MONTH else None,
              "day": value.date.day if value.precision == PartialDate.DAY else None,
          }
      return {"year": None, "month": None, "day": None}

  def value_from_datadict(self, data, files, name):
      # build a PartialDate from the separate fields
      y = data.get(self.year_field % name)
      m = data.get(self.month_field % name)
      d = data.get(self.day_field % name)
      if y == m == d == "":
          return None

      # build the date string
      value = y
      if m:
          value += f"-{m}"
      if m and d:
          value += f"-{d}"

      return value

and the end result in the admin site is this:

I use the widget in my admin classes by specifying it in formfield_overrides, however, it would be fairly trivial to create a custom form field that can be used in any form.

If you like, I'd be happy to write some tests and submit a pull request.