Missing django.forms.widgets.MultiWidget hidden counterpart

[Sayane]

Sometimes it's useful to hide bound field with .as_hidden method. But it's not possible if this field uses MultiWidget. MultiValueWidget doesn't work, because it generates different html names than MultiWidget.

[Sayane]

Oops. Not MultiValueWidget but MultipleHiddenInput.

[Russell Keith-Magee]

Marking this invalid, because I'm not sure I understand the use case. A full example of code that should (but doesn't) work is required.

[Sayane]

For now i'm not shure what it was about. I'll try find this project and I'll provide more informations later.

[Sayane]

I found that.

MultiWidget generates html names like this: "name_0", "name_1", "name_2", "name_x"...
MultipleHiddenInput uses only one name: "name" (but multiple times).

So If i'm using MultiValueField and I'll render a field with as_hidden method (this will put all data in name "name"), then field won't be able to get data from request.POST.

This is why there are SplitDateTimeWidget and SplitHiddenDateTimeWidget in django/forms/widgets.py. I think there should be a hidden field that works with MultiWidget.

[Sayane]

Here is a simple example. MultiLineAddressWidget is a subclass of MultiWidget.

In [26]: w = MultiLineAddressWidget()

In [27]: w.render("myname", ["line1", "line2", "line3"])
Out[27]: u'<input type="text" name="myname_0" value="line1" /><br /><input type="text" name="myname_1" value="line2" /><br /><input type="text" name="myname_2" value="line3" />'

In [28]: w = forms.MultipleHiddenInput()

In [29]: w.render("myname", ["line1", "line2", "line3"])
Out[29]: u'<input type="hidden" name="myname" value="line1" />\n<input type="hidden" name="myname" value="line2" />\n<input type="hidden" name="myname" value="line3" />'

In [30]: 

In [36]: data = {'myname': ['line1', 'line2', 'line3']}

In [37]: w = forms.MultipleHiddenInput()

In [38]: w.value_from_datadict(data, {}, "myname")
Out[38]: ['line1', 'line2', 'line3']

In [39]: w = MultiLineAddressWidget()

In [40]: w.value_from_datadict(data, {}, "myname")
Out[40]: [None, None, None]

I forgot to say that MultiValueField uses MultipleHiddenInput as default hidden widget.

[James Bennett]

1.2 is feature-frozen, moving this feature request off the milestone.

[brianmacdonald]

Attached a patch that adds the feature as a argument of MultipleHiddenInput.

[Julien Phalip]

The tests would need to be rewritten using unittests since this is now Django's preferred way.

[Aymeric Augustin]

Change UI/UX from NULL to False.

[Aymeric Augustin]

Change Easy pickings from NULL to False.

[David Smith]

I've created a pull request to progress this issue.

​https://github.com/django/django/pull/12567

[Mariusz Felisiak]

MultipleHiddenInput was created as a hidden_widget for MultipleChoiceField (see fb60a6ff0acc84417ced061e83bb170fff351b59). It handles multiple hidden widgets for fields that have a list of values (see ​docs), so the same names for all inputs is a desired behavior.

You shouldn't use it as a hiddent_widget for MultiValueField because it's a different use case (multiple fields vs. multiple values).