Add a DateInput widget that provides a date picker via the HTML <input style="date"> element

[dennisvang]

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Background

The forms.DateField uses a ​forms.widgets.DateInput widget, which renders as a standard <input style="text"> in HTML (a simple text box).

It would be very convenient if this widget could provide a date picker by default, similar to date fields on the Django admin site, for example.

There are several options here:

• One could use the ​forms.widgets.SelectDateWidget, but that is not as convenient as a proper calendar date picker.

• One could use the Django ​admin date (and/or time) widgets, but, as far as I know, the admin widgets are not part of the public API, and getting them to work can be a puzzle.

• There are also third-party apps that implement date pickers, but those introduce additional dependencies.

• Last, but not least, ​ modern browsers support the HTML `<input style="date">` element, which provides a very clean solution to the problem described above, without any custom CSS or JavaScript.

Although it is not too difficult to implement a custom widget that uses <input style="date">, one would need to know about it existence first.

Feature request

Would it be possible to provide something like a forms.widgets.BrowserDateInput that leverages <input style="date">?

A crude implementation could look like this:

class BrowserDateInput(forms.widgets.DateInput):
    def get_context(self, name, value, attrs):
        context = super().get_context(name, value, attrs)
        context['widget']['type'] = 'date'
        return context

To set current date and/or minimum/maximum allowable date, we can use the attrs argument. For example:

BrowserDateInput(attrs=dict(value=self.today, min=self.today))

Note that the browser automatically takes care of client-side field validation.

P.S. a similar request could be made for a BrowserTimeInput, although localization could complicate matters here (haven't looked into that yet).