id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
8655	MultiValueField does not render correctly with as_hidden	Bob Thomas	nobody	"MultiValueField needs to define hidden_widget = MultipleHiddenInput so that it will work properly when rendered with as_hidden(). However, MultipleHiddenInput still doesn't render IDs the same way as MultiWidget does, so MultiWidget's value_from_datadict will not find the values that MultipleHiddenInput has rendered. Or something like that. I'm concerned that trying to fix MultipleHiddenInput to work with MultiValueField will break MultipleChoiceField, so fixing this may require another Widget class.

A concrete example for this is using form preview with a SplitDateTimeField. The preview page renders all fields with as_hidden(), which creates a field like
{{{
<input type=""hidden"" name=""delay_start"" value=""[u&#39;2008-08-29&#39;, u&#39;00:00:00&#39;]"" id=""formtools_delay_start"" />
}}}
...which can't be turned back into valid data. It needs to render multiple hidden fields like:
{{{
<input type=""hidden"" name=""delay_start_0"" value=""2008-08-29"" id=""formtools_delay_start_0"" />
<input type=""hidden"" name=""delay_start_1"" value=""00:00:00"" id=""formtools_delay_start_1"" />
}}}
Using MultipleHiddenInput creates 2 hidden fields, but does not append the _i to each name and ID, so the data still does not get read back correctly by the form."		closed	Forms	dev		duplicate			Unreviewed	1	0	1	0	0	0